Background: Pyoderma gangrenosum (PG) is a rare, chronic inflammatory condition exhibiting mucopurulent or hemorrhagic exudates. The majority of cases are associated with inflammatory bowel disease, rheumatological diseases, and hematological malignancies. In the absence of typical serological markers and specific histopathological changes, the diagnosis is often clinical. Being rare, it is frequently misdiagnosed, which leads to a delay in instituting appropriate therapy. Case Presentation: We present a 53-year-old male of Aboriginal descent with end-stage renal disease due to diabetes who underwent insertion of a peritoneal dialysis (PD) catheter. Five weeks after PD catheter insertion, he started to notice a painful ulcer surrounded by a bed of erythema. The lesion eventually progressed to a purulent, hemorrhagic ulcer surrounded by a raised, irregular, violaceous border along the entirety of the PD catheter tunnel. There was no history of underlying systemic diseases commonly associated with PG. The catheter was removed, and an elliptical biopsy was taken, which ruled out infection, malignancy, and vasculitis. The changes were felt to be consistent with PG. The patient underwent treatment initially with topical corticosteroids, followed by oral prednisone, which unfortunately worsened his diabetic control; due to this, he was transitioned to cyclosporine, with complete resolution. Conclusions: Lesions at the PD catheter exit site are usually treated for infections. However, for ulcers that are painful, rapidly expanding, nonhealing, and unresponsive to antibiotics, PG should be considered as a differential diagnosis. This is the first reported case of PG occurring at the exit site of a PD catheter.