RESUMO
OBJECTIVE: To identify the structure, composition and work of the local research ethics committees (LRECs) of the Mexican Institute of Social Security (IMSS) in Mexico. DESIGN: A descriptive cross-sectional study was performed that included all LRECs of the IMSS. METHODS: A total of 335 questionnaires coded in advance were posted to each LREC secretary. The requested information was from January to December 2001. RESULTS: The response rate was 100%. Two hundred and thirty-eight (71%) LRECs were reported as 'active' during the evaluation period. Although almost all LRECs were composed of diverse professionals, physicians dominated the LRECs' membership. The rejection rate for research projects was lower than 1 per 1000, and less than half of the LRECs held meetings to issue a report of projects' evaluation. CONCLUSIONS: LRECs need to foster good ethical research; implementation of an audit system to examine their work might help improve LRECs' performance and accountability.