© 2015 Informa UK Ltd. Objective: To determine if the risk of post-cesarean wound morbidity in patients undergoing staple versus suture closure is modified by diabetic status.Methods: Secondary analysis of a randomized trial of skin closure with subcuticular 4-0 monocryl suture or surgical staples after cesarean delivery. The primary outcome was a composite of wound disruption or infection within 4-6 weeks. We compared the association between this outcome and skin closure method by diabetic status (also stratified by gestational or pregestational) using the Breslow-Day test for interaction.Results: Of 350 patients, 179 were randomized to staples and 171 to suture. Of the 67 (19.1%) diabetic patients, 35 were gestational and 32 pregestational. The incidence of composite wound morbidity in non-diabetics was 16.7% for staples and 3.6% for suture (p ≤ 0.001, RR: 4.6, 95% CI: 1.8-11.8); it was 5.7% for staples and 15.6% for sutures in diabetics (p = 0.25, RR: 0.4, 95% CI: 0.1-1.7). The corresponding Breslow-Day p value indicated a significant difference between diabetics and non-diabetics (p = 0.002). Stratified further by gestational and pregestational diabetes, the RRs were 0.3 (95% CI: 0.03-2.4) and 0.5 (95% CI: 0.05-5.0) compared to non-diabetics, respectively. Each diabetic sub-group was significantly different from non-diabetics (Breslow-Day p values for homogeneity p = 0.005 and p = 0.045, respectively).Conclusions: The use of staples compared with subcuticular suture for cesarean skin closure is associated with increased wound morbidity. While this is true for non-diabetics, further studies of diabetics are needed to evaluate for a null or opposite effect of closure type.