We conducted a descriptive and cross-sectional study with 242 medical undergraduates at two public universities and two private colleges in Teresina, Piauí. A semi-structured questionnaire to understand how human sexuality was taught in medical courses was applied. The questionnaire response rate was 86.3%. The teaching of sexuality was identified by 95.2% of students at some time during the course. Gynecology was the discipline that discussed sexuality the most (91.9%), followed by Psychiatry (55.3%), Medical Psychology (30.6%) and Urology (24.1%). Sexuality was cited as a specific topic in only 8.4% of the reports, but it was reported in classes about other topics such as cancer (70.9%), abortion (67.5%), STD and HIV/AIDS (67%). In class, the teacher emphasized sexual dysfunctions (84.1%), with less emphasis on homosexuality (50%) and sexual and reproductive rights (40.6%). Students indicated that there were positive influences of sexual education in undergraduate study (96.1%). There was great emphasis on the discussion of biological aspects and diseases associated with sexuality, with less emphasis on the social construction of the theme and sexual orientation.