Background: Pyoderma gangrenosum is a rare inflammatory disease of unknown etiology and a poorly understood pathogenesis.Its clinical presentation is variable and a large percentage of cases are associated with inflammatory bowel diseases.Peristomal pyoderma gangrenosum represents a variant of the diseases, occurring in patients with colostomy.Multiple cases demonstrate efficacy of infliximab and other anti-TNF-alpha drugs in treatment of pyoderma gangrenosum.Main observations: A 47-year-old male with ulcerative colitis and proctocolectomy with ileal pouch reconstruction protected by ileostomy in the course of diseases received infliximab therapy together with azathioprine for his inflammatory bowel diseases.Six months after initiation of infliximab therapy the patient developed multiple pyoderma gangrenosum lesions on the trunk, abdomen, genitalia, gluteus, extremities, left preauricular region and peristomal area.After systemic corticosteroid therapy, combined with topical tacrolimus, the lesions slowly improved.Seven months later, during ongoing infliximab therapy, the patient developed a sepsis with fatal outcome. Conclusion:Constant trauma generated by colostomy may be a contributing factor to the development and persistence of pyoderma gangrenosum.It may be hypothesized that this patient developed pyoderma gangrenosum despite infliximab or that pyoderma gangrenosum may represent a rare adverse effect of the drug.