Pyoderma gangrenosum (PG) is a severe ulcerative skin disease. Despite systemic immunosuppressive therapy, PG ulcers often progress and can develop into life-threatening conditions. In this case series, we treated 6 patients suffering from recalcitrant PG with topical coagulation factor XIII, which has been shown to exert beneficial effects on tissue regeneration and wound healing. All 6 patients showed a positive response to treatment with a marked reduction in wound size that was maintained during a 3-month follow-up period. The treatment was well tolerated with no remarkable adverse effects or complications. Topical factor XIII has potential in combination with standard immunosuppressive therapy for the treatment of PG.