Objectives: To measure the impact of clusters of double triggering on clinical outcomes., Design: Prospective cohort study., Setting: Respiratory ICU in Brazil., Patients: Adult patients under recent mechanical ventilation and with expectation of mechanical ventilation for more than 24 hours after enrollment., Interventions: None., Measurements and Main Results: We used a dedicated software to analyze ventilator waveforms throughout the entire period of mechanical ventilation and detect double triggering. We defined a cluster of double triggering as a period of time containing at least six double triggering events in a 3-minute period. Patients were followed until hospital discharge. We addressed the association between the presence and the duration of clusters with clinical outcomes. A total of 103 patients were enrolled in the study and 90 (87%) had at least one cluster of double triggering. The median number of clusters per patient was 19 (interquartile range, 6-41), with a median duration of 8 minutes (6-12 min). Compared with patients who had no clusters, patients with at least one cluster had longer duration of mechanical ventilation (7 d [4-11 d] vs 2 d [2-3 d]) and ICU length of stay (9 d [7-16 d] vs 13 d [2-8 d]). Thirty-three patients had high cumulative duration of clusters of double triggering (≥ 12 hr), and it was associated with longer duration of mechanical ventilation, fewer ventilator-free days, and longer ICU length of stay. Adjusted by duration of mechanical ventilation and severity of illness, high cumulative duration of clusters was associated with shorter survival at 28 days (hazard ratio, 2.09 d; 95% CI, 1.04-4.19 d)., Conclusions: Clusters of double triggering are common and were associated with worse clinical outcomes. Patients who had a high cumulative duration of clusters had fewer ventilator-free days, longer duration of mechanical ventilation, longer ICU length of stay, and shorter survival than patients with low cumulative duration of cluster., Competing Interests: Dr. Sousa received funding from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), grant number 2015/19122-4. Dr. Magrans disclosed they are an employee of Better Care S.L., the software development company that has developed the platform used in this research to capture, process, and analyze the respiratory waveforms. Dr. Blanch disclosed that he is the inventor of one Corporació Sanitaria Parc Taulí owned U.S. patent: “Method and system for managed related patient parameters provided by a monitoring device,” U.S. Patent No. 12/538,940, and founder of BetterCare S.L., which is a research and development company, startup of Corporació Sanitària Parc Taulí. Dr. Kacmarek’s institution received funding from Research Grant Orange Medical, Medtronic, Orange Medical, Venner Medical, and Nihon Kohden. Dr. Ferreira’s institution received funding from FAPESP (Brazilian funding agency), and she received funding from Medtronic. Dr. Hayashi has disclosed that she does not have any potential conflicts of interest., (Copyright © 2021 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)