The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, staging and treatment of patients with metastatic breast cancer (MBC) was published in 2021. A special, hybrid guidelines meeting was convened by ESMO and the Korean Society of Medical Oncology (KSMO) in collaboration with nine other Asian national oncology societies in May 2022 in order to adapt the ESMO 2021 guidelines to take into account the differences associated with the treatment of MBC in Asia. These guidelines represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with MBC representing the oncological societies of China (CSCO), India (ISMPO), Indonesia (ISHMO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO). The voting was based on the best available scientific evidence and was independent of drug access or practice restrictions in the different Asian countries. The latter were discussed when appropriate. The aim of these guidelines is to provide guidance for the harmonisation of the management of patients with MBC across the different regions of Asia, drawing from data provided by global and Asian trials whilst at the same time integrating the differences in genetics, demographics and scientific evidence, together with restricted access to certain therapeutic strategies., Competing Interests: Disclosure MLTAT declares consulting fees and honoraria from MSD, Roche, Novartis, Eli Lilly and AstraZeneca. HKA declares consulting fees from Daiichi Sankyo, Amgen, Yuhan and Novartis, and honoraria from Roche, BMS, MSD, Eli Lilly, AstraZeneca, Boehringer Ingelheim, Menarini, Eisai, Pfizer, Boryung Pharmaceutical Company, Celtrion, Pharmobio Korea Inc. and Yuhan. GC has served as consultant or advisor for Roche, Eli Lilly and BMS; served on a speaker’s bureau for Roche, Pfizer and Eli Lilly; received travel funding from Pfizer and Roche; and received honoraria from Roche, Pfizer, Eli Lilly, Novartis, AstraZeneca and SeaGen, all outside the submitted work. THF declares honoraria from AstraZeneca Oncology Indonesia, Takeda Indonesia, Eisai Indonesia, Roche Oncology Indonesia, J & J Indonesia and Zueling Pharma Indonesia and role as head of division of Area Development for West Java, Indonesia for the Indonesian Society of Hematology and Medical Oncology. AG declares honoraria for advisory boards from AstraZeneca, Daiichi Sankyo, Eisai, Eli Lilly, Novartis, Pfizer and Roche; honoraria for lectures from Eisai and Eli Lilly and honoraria for expert testimony from Gentili. SG declares honoraria from Lupin, Roche, Novartis, Eli Lilly, Eisai, Cipla, CADILA, Intas and AstraZeneca; honoraria for being on committees of the Indian Council of Medical Research (Government of India), Council of Scientific and Industrial Research (Government of India), Department of Biotechnology (Government of India), India Alliance and institutional; honoraria from Novartis and AstraZeneca for participation in steering committees; leadership roles include President of Indian Society of Medical and Paediatric Oncology and General Secretary of Women’s Cancer Initiative - Tata Memorial Hospital, both roles unpaid. NH reports honoraria for lectures, advisory boards and/or personal fees from Amgen, AstraZeneca, Daiichi Sankyo, Eli Lilly, MSD, Novartis, Pfizer, Pierre Fabre, Roche, Sandoz and SeaGen, and minority ownership interest in the West German Study Group. RAH declares honoraria from Roche, Novartis, MSD, Pfizer and Mylan, and support for attending meetings from Roche, MSD and Kalbe Pharma. SAI declares an institutional grant from AstraZeneca, Boryung Pharm, Daewoong Pharm, Eisai, Roche and Pfizer, and honoraria from AstraZeneca, Novartis, MSD, Roche, Pfizer; advisory role for AstraZeneca, Bertis, Daiichi Sankyo, Eisai, Hanmi, Lilly, MSD, Novartis, Roche and Pfizer. JHK declares an institutional grant from Ono Pharma Ltd., and honoraria from Novartis, MSD, Roche Pharma, Roche diagnostics, Pfizer, AstraZeneca, Eisai, Lilly, and Sanofi; fees for participation in data monitoring or advisory boards from Bixink, Eisai, Yuhan, Novartis, Daiichi Sankyo, Pfizer, Roche Pharma and Everest Medicines; institutional gifts from Eisai and Ono Pharma Ltd. SBK declares institutional funding from Novartis, Sanofi-Aventis and Dongkook Pharm Co.; consulting fees from Novartis, AstraZeneca, Lilly, DaeHwa Pharmaceutical Co Ltd., ISU Abxis, Beigene, OBI Pharma and Daiichi Sankyo; honoraria from Novartis, Pfizer, Lilly, OBI Pharma and Legochem Bioscience; participation on data safety monitoring or advisory boards for Novartis, AstraZeneca, MSD, Lilly and Daiichi Sankyo, and purchased stock in Genopeaks and Neogene TC. KHL declares honoraria from Pfizer, Novartis and Eli Lilly. SCL declares grants from Pfizer, Eisai, Taiho, ACT Genomics, MSD, Adagene and Epizyme; honoraria from Pfizer, Novartis, AstraZeneca, ACT Genomics, Eli Lilly, MSD and Roche and participation in data monitoring or advisory boards for Pfizer, Novartis, Eisai, Sanofi, Daiichi Sankyo, MSD and Roche. MYM declares institutional grants from MSD, Astella, Pfizer, Novartis, AstraZeneca, ARCUS, Amgen and honoraria from MSD, Amgen, Pfizer, Roche, Novartis, Zuelling Pharma, Specialised therapeutics, Eisai, GSK, Mundi Pharma, Eli Lilly and AstraZeneca. YN declares institutional grants from the Ministry of Health, Labour and Welfare, Abbvie, Ono, Daiichi Sankyo, Taiho, Pfizer, Boehringer Ingelheim, Eli Lilly, Eisai, AstraZeneca, Chugai, Bayer and honoraria from AstraZeneca, Eisai, Ono, Gardant, Takeda, Eli Lilly, Novartis, Pfizer, Chugai, Fuji Film Toyama Chemistry, Taiho, Mundi, Bristol, Shionogi. NP declares honoraria from AstraZeneca, Eisai, Roche, Eli Lilly, Novartis, Pfizer and MSD. YHP declares grants from AstraZeneca, Pfizer, Novartis, Roche and Gencurix, consulting fees from AstraZeneca, Pfizer, Novartis, Roche, Eisai, Daiichi Sankyo, MSD and Lilly, honoraria from Pfizer, MSD, Novartis and Roche, and participation on data monitoring boards and advisory boards for Roche, Eisai, Daiichi Sankyo, AstraZeneca, MSD and Novartis. SP declares fees for consultancy/advisory roles from Abbvie, Amgen, Arcus, AstraZeneca, Bayer, Beigene, Bio Invent, Biocartis, Blueprint Medicines, Boehringer Ingelheim, BMS, Daiichi Sankyo, Debiopharm, ecancer, Eli Lilly, Elsevier, F-star, Foundation Medicine, Genzyme, Gilhead, GSK, Illumina, Incyte, IQIVIA, iTHeos, Janssen, Medscape, MSD, Merck Serono, Mirati, Novartis, Novocure, Pharma Mar, Phosplatin Therapeutics, Pfizer, Regeneron, Roche/Genentech, Sanofi, SeaGen, Takeda, Vaccibody, speaker roles for AstraZeneca, Boehringer Ingelheim, BMS, ecancer, Eli Lilly, Fishawack, Illumina, Imedex, Medscape, Mirati MSD, Novartis, OncologyEducation, PER, Pfizer, PRIME, RMEI, Roche/Genentech, RTP, Sanofi, Takeda and steering committee and trial chair roles as follows: AstraZeneca, coordinating PI, institutional, no financial interest, MERMAID-1; AstraZeneca, steering committee member, institutional, no financial interest, MERMAID-2, POSEIDON, MYSTIC; Beigene, steering committee member, institutional, no financial interest, BGB-A317-A1217-301/AdvanTIG-301; BMS, steering committee member, institutional, no financial interest, clinical trial steering committee CheckMate 743, CheckMate 73L, CheckMate 331 and 451; BMS, steering committee member, institutional, no financial interest, RELATIVITY 095; GSK, trial chair, institutional, no financial interest, clinical trial chair ZEAL-1; iTeos, steering committee member, institutional, no financial interest, Phase 2 Inupadenant with chemo; Mirati, steering committee member, institutional, no financial interest, clinical trial steering committee SAPPHIRE; MSD, steering committee member, institutional, no financial interest, clinical trial steering committee PEARLS, MK-7684A; Pharma Mar, steering committee member, institutional, no financial interest, LAGOON; Phosplatin Therapeutics, steering committee member, institutional, no financial interest, phase 1/2 trials; Roche/Genentech, trial chair, institutional, no financial interest, clinical trial chair Skyscraper-01; chair ALEX; steering committee BFAST; steering committee BEAT-Meso; steering committee ImPower-030, IMforte. Also role as ESMO president, ETOP/EORTC/SAKK PI, involved in academic trials, ETOP/IBCSG partners officer. Council member and scientific chair, SAKK, vice-President Lung Group, SAMO, Vice President. BKS declares honoraria from Novartis and Eli Lilly. MS declares honoraria from AstraZeneca, MSD, Accord Health and Novartis, support for attending meetings from the Malaysia Urology Association and roles as an ex-committee member of the Malaysian Oncological Society and chairman of the Annual Scientific congress of the Malaysian Oncological Society. KT declares grants from Pfizer, Daiichi Sankyo, Eli Lilly, AstraZeneca, Eisai; honoraria from Daiichi Sankyo, Eli Lilly, Chugai, MSD; and data monitoring or advisory board fees from Daiichi Sankyo. SSW declares a grant from Pfizer and honoraria from Pfizer, Roche, AstraZeneca, Novartis, Daiichi Sankyo, Eli Lilly, MSD and Henrui. TY declares institutional grants from Amgen, Boehringer Ingelheim, Chugai, Daiichi Sankyo, Genomedia, MSD, Ono, Pfizer, Sanofi, Sysmex and Taiho, and honoraria Bayer, Chugai, Merck biopharma, MSD and Ono. All other authors have declared no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)