PURPOSE: To evaluate abdominal wall closure knowledge base and technical skills in surgical and OB/GYN residents. METHODS: Residents consented to participate in a skills laboratory and quiz. The skills portion involved closure of a 10-cm incision on a simulated abdominal wall. Participants were timed, filmed, and graded using a standardized grading system. RESULTS: Thirty surgical and OB/GYN residents participated. All residents reported closing the abdominal wall continuously, 97% preferred slowly absorbing sutures (28/29), 97% preferred taking 1-cm bites (29/30), and 93% spaced bites 1 cm apart (27/29). However, 77% (10/13) of surgery residents identified 4:1 as the ideal suture to wound length ratio; 47% (7/15) of OB/GYN residents believed it to be 2:1, and another 40% (6/15) indicated 3:1 (p < 0.0001). In the simulation, OB/GYN residents used significantly fewer stitches (p = 0.0028), significantly more distance between bites (p < 0.0001), and significantly larger bite size (p < 0.0001) than surgery residents. When graded, there was no significant difference between programs. CONCLUSIONS: Despite some knowledge regarding the principles of abdominal wall closure among surgical and OB/GYN residents, more instruction is needed. We identified some differences in knowledge base and techniques for abdominal wall closure among general surgery and OB/GYN residents, which are likely due to differences in educational curriculums.