Lesbian, gay, bisexual, and transgender (LGBT) individuals experience health and health care disparities and have specific health care needs. Medical education organizations have called for LGBT-sensitive training, but how and to what extent schools educate students to deliver comprehensive LGBT patient care is unknown. To characterize LGBT-related medical curricula and associated curricular development practices and to determine deans' assessments of their institutions' LGBT-related curricular content. Deans of medical education (or equivalent) at 176 allopathic or osteopathic medical schools in Canada and the United States were surveyed to complete a 13-question, Web-based questionnaire between May 2009 and March 2010. Reported hours of LGBT-related curricular content. Of 176 schools, 150 (85.2%) responded, and 132 (75.0%) fully completed the questionnaire. The median reported time dedicated to teaching LGBT-related content in the entire curriculum was 5 hours (interquartile range [IQR], 3-8 hours). Of the 132 respondents, 9 (6.8%; 95% CI, 2.5%-11.1%) reported 0 hours taught during preclinical years and 44 (33.3%; 95% CI, 25.3%-41.4%) reported 0 hours during clinical years. Median US allopathic clinical hours were significantly different from US osteopathic clinical hours (2 hours [IQR, 0-4 hours] vs 0 hours [IQR, 0-2 hours]; P = .008). Although 128 of the schools (97.0%; 95% CI, 94.0%-99.9%) taught students to ask patients if they "have sex with men, women, or both" when obtaining a sexual history, the reported teaching frequency of 16 LGBT-specific topic areas in the required curriculum was lower: at least 8 topics at 83 schools (62.9%; 95% CI, 54.6%-71.1%) and all topics at 11 schools (8.3%; 95% CI, 3.6%-13.0%). The institutions' LGBT content was rated as "fair" at 58 schools (43.9%; 95% CI, 35.5%-52.4%). Suggested successful strategies to increase content included curricular material focusing on LGBT-related health and health disparities at 77 schools (58.3%, 95% CI, 49.9%-66.7%) and faculty willing and able to teach LGBT-related curricular content at 67 schools (50.8%, 95% CI, 42.2%-59.3%). The median reported time dedicated to LGBT-related topics in 2009-2010 was small across US and Canadian medical schools, but the quantity, content covered, and perceived quality of instruction varied substantially.