OBJECTIVE : To characterize the mistreatment identified within the University of Michigan's Obstetrics and Gynecology (Ob/Gyn) clerkship and compare the rates of mistreatment to that of other clerkships in an effort to improve the learning environment. METHODS : This is a retrospective cohort study looking at multiple sources of data from 2015 to 2018 about student mistreatment including end-of-rotation and teaching evaluations completed by students, as well as an online reporting system available to medical students. For evaluations, students were asked to rate their agreement with statements on a 5-point Likert scale (1 = strongly disagree, to 5 = strongly agree). Narrative comments were also solicited and evaluated. METHODS : University of Michigan Medical School and Michigan Medicine Ob/Gyn Department, Ann Arbor, Michigan. METHODS : A total of 513 students rotated through the Ob/Gyn clerkship between 2015 and 2018 and were asked to complete evaluations. RESULTS : Five hundred and five of the 513 students completed evaluations between 2015 and 2018. In response to the statement, "Students are treated in a professional/respectful manner in this clerkship," the Ob/Gyn clerkship's mean scores on a 5-point scale were 4.45 (in 2015-2016), 4.52 (in 2016-2017), and 4.27 (in 2017-2018). These means, as well as the means to 3 other professionalism questions, were lower than the range of 4.42 to 4.84 for all other third-year clerkships over this time. The mean scores were also lower for Ob/gyn when compared to the Surgery clerkship. A total of 32 narrative comments were submitted by students between 2015 and 2017 related to mistreatment or unprofessional behavior. Frequent themes included students being treated as "stupid" or discouraged from asking questions (8 comments), being treated in an unprofessional manner by staff (7 comments), feeling ignored or marginalized by faculty (4 comments), and faculty unprofessional behavior toward others (4 comments). CONCLUSIONS : Students on the Ob/Gyn clerkship reported a higher rate of mistreatment compared to other clerkships. Efforts are being made by the Ob/Gyn department to communicate these data on mistreatment to educators in order to improve the Ob/Gyn culture and learning environment for medical students.