OBJECTIVE Abdominal bulging and incisional hernia are known sequelae after open partial nephrectomy (OPN) via a flank incision. Precise rates are not known. The aims of this study were to determine the rates of bulging and hernia after OPN, and to examine potential risk factors. MATERIALS AND METHODS A retrospective review was undertaken of 197 consecutive patients operated on with OPN via a flank incision between 2004 and 2014. After exclusion, 184 patients remained. Medical records and radiological images from the preoperative work-up, and follow-up after surgery at 3, 12 and 24 months, were reviewed. RESULTS A visible bulge was noted in 36 of the 184 patients at clinical examination. Only 20 cases (12%) remained at the last follow-up. Radiological changes interpreted as a bulge were initially seen in 50 patients, while only 35 (19%) remained at the last radiological examination. Clinical incisional hernia was reported in five patients (3%), and radiological hernia was seen in 10 patients (5%). Patients who developed a hernia had a higher body mass index (30 vs 26 kg/m2, p = 0.02). Other demographic variables showed no significant correlation. CONCLUSIONS Bulging is a common sequela after flank incision. The rate of incisional hernia after flank incision is comparable to rates after other forms of abdominal surgery. Further studies are required to evaluate the psychological and physiological effects of bulging, the pain and weakness caused, and the cosmetic embarrassment suffered by the patient.