ABSTRACT: The aim of this study was to identify the characteristics of morbidity and mortality conferences (MMCs) associated with the implementation of patient health-care quality and safety improvement initiatives.We conducted an observational study of MMCs and followed up improvement initiatives for 1 year. Data on MMC baseline characteristics were abstracted using document analysis and observation of a meeting in three university hospitals in France (Grenoble, Nice, and Cochin [Paris] hospitals). Fifty-nine MMCs were included in medical (n?=?24), surgical (n?=?21), and anesthesiology and/or intensive care (n?=?14) departments. An effectiveness index was computed by summing a composite score for each initiative pertaining to the MMC.Overall, 282 initiatives were identified in 42 MMCs. During the follow-up period, 215 initiatives (76%) were totally or partially implemented and the impact was evaluated for 73 (26%). An effectiveness index higher than the median (i.e., ?10) was associated with a standardized presentation of cases (81% versus 29%, p <0.001), recording of improvement initiatives (94 versus 57, p?=?0.001), the existence of an annual activity report (94% versus 68%, p?=?0.01), the prior dissemination of a meeting agenda (71% versus 36%, p?=?0.007), longer meeting duration (109 versus 80 min, p?=?0.005), anesthesiology and/or intensive care specialty (39% versus 7%, p?=?0.02), a theme-focused MMC (29% versus 4 %, p?=?0.01), and a thorough analysis of failures (58% versus 25%, p?=?0.01).This study suggests that the implementation of improvement initiatives relates to MCC characteristics. Recommendations for developing more effective patient safety-oriented MMCs can be proposed.