Peritoneal spread is a typical feature in patients with primary advanced or recurrent ovarian cancer. Since the first report by Griffith [
1] multiple retrospective series have shown that survival is inversely proportional to residual tumor size [
2]. After a meta-analysis showed that maximal cytoreduction improves prognosis [
3], the criteria for defining desirable surgical outcome in advanced ovarian cancer (AOC) switched from 'optimal debulking’ with variable residual disease up to 1 to 2 cm in diameter, to microscopic residual disease alone. These findings justified more aggressive surgery including, as in other peritoneal carcinomatoses, hyperthermic intraperitoneal chemotherapy (HIPEC) [
4,
5]. In patients with extensive peritoneal spread from AOC, bulky upper abdominal disease often precludes optimal cytoreduction thus lowering survival rates [
6]. To achieve better cytoreduction rates and improve outcome, centers highly experienced in treating AOC, therefore, now recommend extending standard cytoreduction with extensive upper abdominal surgical procedures, including subphrenic peritonectomy, splenectomy, distal pancreatectomy or tumor stripping from Glisson’s capsule [
7‐
9]. Diaphragmatic surgery includes various procedures, such as subphrenic peritonectomy originally proposed by Sugarbaker (stripping) [
10], coagulating minimal lesions less than 5 mm in diameter or, in patients with extensive spread infiltrating the muscle and sometimes the adjacent pleura, full-thickness resection [
8]. Diaphragmatic surgery carries its own specific morbidity, mainly including pleural and pulmonary complications (pleural effusions, pneumothorax, pulmonary infections and the need for intrathoracic drainage). Less frequently, it also leads to morbidity related to the other upper abdominal surgical procedures frequently associated with subphrenic peritonectomy, such as splenectomy or distal pancreatectomy leading to pancreatitis, digestive fistulas or abdominal collections [
9,
11,
12]. This case report describing a patient in whom a delayed diaphragmatic hernia manifested after cytoreductive surgery including subphrenic peritonectomy for AOC underlines the need to take this possible late complication related to these multiple upper abdominal surgical procedures into account during postoperative follow-up.