Abstract Background and Aims Peritoneal Dialysis (PD) is currently the first option as renal replacement therapy to many patients, for several reasons, as personal flexibility, volemic management in cardiorenal patients, poor vascular access to dialysis, among others. Mechanical complications can be a drawback in these patients, which may occur during or after catheter placement. Abdominal wall hernias and dialysate leaks are relatively common and highly related to chronically increased intraperitoneal pressure. In this setting CT peritoneography is the technique of choice as it allows differentiation between a true hernia or a wall leakage. Method We describe a case of a 69-year-old man, with a personal history of polycystic kidney disease, colonic diverticulosis and hypertension, which opted for PD. The patient later developed a mechanical complication for which a proper diagnostic approach, namely through specific imaging, and surgical planning were essential. Results After 15 months without complications, it was detected a bulging in the periumbilical area, exacerbated by orthostatism. Changes in dialytic prescription included lower dialytic volumes during orthostatic period, with some improvements. The limitation of volumes and difficulty of drainage were limiting dialytic prescription and insufficient kt/V. An ultrasound (figure 1) and CT peritoneography (figure 2) were performed, revealing an hernial sac with peritoneal liquid leak, without any intestinal loop, approachable by minimally invasive surgery and local anesthesia. Mini-laparotomy was performed, hernial sac was removed, without peritoneum aperture, with only a 4-day pause on PD technique. Conclusion CT peritoneography allowed the differentiation between this true hernia and a wall leakage, by providing accurate anatomical detail, allowing proper planning of surgical intervention. In this case, the patient had additional predisposing factors, namely polycystic kidney disease. Moreover, only a short pause on PD was necessary. Although some limitations exist, such as the use of iodinated contrast material and ionizating radiations, CT peritoneography is currently the gold standard for the evaluation of mechanical complications in PD; in addition to those mentioned, it is also useful for complications related to the catheter (kinking, entrapment, malposition), intrabdominal adhesions or loculated fluid collections.