Objectives: to define the most frequent health pathways of cases affected by malignant pleural mesothelioma according to those suggested and evaluated by the most recent specific guidelines., Design: epidemiological descriptive study., Setting and Participants: 100 cases histologically or cytologically well defined during 2015-2017 are extracted from the archive of two Regional Mesothelioma Registries: in Tuscany Region (Central Italy) they are randomly extracted, while in Lombardy Region (Northern Italy) cases treated by a highly-specialized health centre are collected., Main Outcome Measures: frequency of the diagnostic and therapeutic procedures; development and application of the checklist with evaluation of the duration of some phases of the predefined pathway., Results: all hospital medical records were collected only for 34 cases in Tuscany and 20 cases in Lombardy. The health examinations were supplied according to each case's health condition and it was not possible to define one or more structured and standardized pathways. The pre-diagnostic phase has a variable duration according to the initial health condition of the patient, also for his/her comorbidity, and to the hospital where he/she was hospitalized at first. The examinations in outpatient services (medical examinations, blood chemistry tests and radiological examinations) are several, but they are specially requested during the pre-diagnostic phase and during the period of chemotherapy. The checklist applied to a subset of Tuscan cases shows a large variation of the length of the pre-diagnostic phase (6-330 days), of the time interval between diagnosis and reporting to mesothelioma registry (1-200 days), and of the survival time (8 days - alive at 31.12.2019)., Conclusions: to obtain the best health pathways for malignant pleural mesotheliomas, it is necessary a strong network among the health regional services with a clinical multiprofessional coordination located in hospitals characterized by a long experience on these cases, and with an active regional monitoring on all clinical, psychological, epidemiological, and legal aspects of the pathway. The regional mesothelioma registries could give a high contribution thanks to their epidemiological skills which are necessary for the monitoring., Competing Interests: None declared