PURPOSE: To evaluate the clinical features and incidence of separation of the symphysis pubis during childbirth, and to evaluate the risk factors of the lesion and the outcome of treatment. MATERIALS AND METHODS: Seventy two cases of separation of symphysis pubis among 66,721 delivery between January 1992 and December 2004 was selected. The control group was composed of 498 cases without separation of symphysis pubis during childbirth. Several factors increasing the risk of this lesion were assessed using χ²-test and Student t-test. The final outcome was evaluated on radiographs and the grading system of Majeed. RESULTS: Mean width of the joint was initially 13.8 mm (range, 6~43) and finally 4.9 mm (range, 3~16). Onset of symptoms occurred variably from labor to postpartum day 3. Incidence of separation of symphysis pubis was one among 927 deliveries. The separation group differed significantly from the control with respect to birth weight, the prolonged 2nd stage of labor, and the use of vacuum-delivery. Of 63 cases at final, 52 cases (82.5%) had excellent result, 9 (14.3%) had good and 2 (3.2%) had fair. CONCLUSION: The result showed that high birth weight, the prolonged second stage of labor and vacuum-delivery were risk factors of separation of the symphysis pubis during childbirth. This lesion was treated well with conservative methods, although variable radiological findings were noted at final follow-up.