Our objective was to assess the incidence, risk factors and clinical outcomes of dehiscence after foot surgery in diabetic patients. We used pooled patient‐level data from two randomised clinical trials with 240 diabetic patients who required foot surgery for infections. Most patients (n = 180, 75.0%) had surgical wound closure. We defined dehisced surgical wounds (DSW) when the surgical site was not completely epithelialized with no drainage after sutures/staples were removed with a 2‐week validation of healing. We evaluated the time to heal, re‐infection, re‐ulceration, hospital admissions and amputations. Moderate and severe infection was based on criteria of the International Working Group on the Diabetic Foot. We used χ2 and t‐test and Mann–Whitney U for comparison of clinical events, with α of <0.05. DSW occurred in 137 (76.1%) patients. DSW patients were more likely to have hypertension (62.8% vs. 81.8%, p = 0.01), high ESR (59.1 ± 37.9 vs. 75.9 ± 37.6, p = 0.01), low toe brachial indices (0.8 ± 0.2) (0.7 ± 0.2, p = 0.005), toe brachial indices <0.6 (16.7% vs. 40.9%, p = 0.008), and low skin perfusion pressure measurements (dorsal medial 71.0 ± 29.4 vs. 59.3 ± 23.3, p = 0.01, and plantar medial 81.8 ± 24.9 vs. 72.2 ± 20.4, p = 0.02). During 12‐month follow‐up, DSW patients were 12.9 times more likely to have re‐infection (0% vs. 12.4%, p = 0.02) and 6.8 times more likely to require amputation (2.3% vs. 13.9%, p = 0.04). The median healing time (28, 22.5–35.0 vs. 114.0, 69.0; 365, p = 0.001), and median length of hospitalisation were longer in DSW patients (12.0, 9.01–9.0 vs. 15.0, 11.0–24.0, p = 0.04). There was a high incidence of DSW, associated with poor clinical outcomes.