Objective: To develop an objective structured assessment for evaluating surgical skills of obstetrics and gynecology residents and to evaluate the reliability and validity of the assessment. Methods: A seven-station, objective, structured assessment of technical skills was administered to 24 residents. The test included laparoscopic procedures (port placement, salpingostomy, suturing, vessel ligation) and open abdominal procedures (hypogastric ligation, repair of enterotomy, salpingo-oophorectomy.) All surgical tasks were done on pigs. Residents were timed and assessed at each station using three methods of scoring, a task-specific checklist, global rating scale, and pass-fail grade. Results: Assessment of construct validity (the ability of the test to discriminate among residency levels) found significant differences on the checklist and the global rating scale by residency level. Reliability indices calculated with Cronbach’s α were 0.89 for the global rating scale and 0.89–0.95 for the individual skills checklists. Interrater reliability was 0.87 for the global rating scale and 0.78–0.98 for the checklists. Conclusion: Objective, structured assessment of technical skills can assess residents’ surgical skills with high reliability and validity. These assessments have possible application for identifying residents who need additional training and might provide a mechanism to ensure competence of surgical skills.