A 32-year-old woman with ulcerative colitis had a relapsed of pyoderma gangrenosum during puerperium. Both the pyoderma gangrenosum and ulcerative colitis had been well controlled with oral prednisolone, but ulcerative colitis relapsed in pregnancy, and pyoderma gangrenosum relapsed in the puerperium. The pyoderma gangrenosum responded to methylprednisolone pulse therapy initially, but relapsed when prednisolone was tapered. A second trial of pulse therapy combined with cyclosporine resulted in complete remission of the pyoderma gangrenosum, and no recurrence was recognized after prednisolone was tapered. This is a very rare case of successful treatment with methylprednisolone pulse therapy combined with cyclosporine for pyoderma gangrenosum complicating ulcerative colitis.