OBJECTIVE: Closure of a low transverse cesarean incision with one layer of suture results in less operating time, better hemostasis, and less infectious morbidity than a two-layer closure. STUDY DESIGN: At our institution 906 women were randomized to closure of a low transverse cesarean incision with either one continuous layer of a locking No. 1 chromic suture and a CTX needle (n = 457) or two continuous layers of No. 1 chromic suture with the first layer locked (n = 449). The Student t test, χ2 test of proportion, and Wilcoxon rank sum test were used to compare groups of patients. RESULTS: A one-layer closure required less operative time, 43.8 versus 47.5 minutes (p = 0.0003).Fewer additional uterine hemostatic sutures were required in 369 women in whom either the one- (n = 179) or the two-layer (n = 190) closure did not achieve hemostasis (p = 0.046). Endometritis was similar in both groups, 83 (22%) in the one-layer group versus 65 (18%) in the two-layer group (p = 0.17). In no outcome assessment was the two-layer closure superior to the one-layer closure. CONCLUSION: We recommend a one-layer closure when its use is anatomically feasible. (Am J OBstetGYnecol 1992;167:1108–11.) © 1992, Mosby. All rights reserved.