We report here a very rare case of intestinal Behcet’sdisease with pyoderma gangrenosum.A 16-year-oldwoman who was diagnosed with intestinal Behcet’sdisease by the presence of cutaneous pathergy togetherwith two major criteria(oral and genital aphthoses)andone minor criterion(gastrointestinal manifestations),wasreferred to our hospital with a left lower leg ulcer andabdominal pain in September 1989.Colonoscopy dem-onstrated flare-up colitis involving the entire colon.Herlower leg lesion was a painful destructive ulcer with anirregular margin and a ragged overhanging edge.Basedon these clinical and laboratory findings,we diagnosedher cutaneous ulcer as pyoderma gangrenosumdeveloping with exacerbated intestinal Behcet’s disease.Her cutaneous and intestinal lesions were poorlycontrolled though she received oral prednisolone treat-ment for a month.Because of aggravated abdominalsymptoms with peritoneal irritation,we performed totalcolectomy in November 1989.The resected specimenwas histologically compatible with intestinal Behcet’s disease showing severe inflammation with deepulcerations and neutrophil accumulation.Subsequently,pyoderma gangrenosum rapidly improved.This clinicalcourse may suggest the close relationship betweenpyoderma gangrenosum and intestinal Behcet’s disease. We report here a very rare case of intestinal Behcet’s disease with pyoderma gangrenosum. A 16-year-oldwoman who was diagnosed with intestinal Behcet’s disease by the presence of cutaneous pathergy together with two major criteria (oral and genital aphthoses) andone minor criterion ( gastrointestinal manifestations), wasreferred to our hospital with a left lower leg ulcer and abdominal pain in September 1989. Colonoscopy dem-onstrated flare-up colitis involving the entire colon. Herlower leg lesion was a painful destructive ulcer with an irregular margin and a ragged overhanging edge. Basedon these clinical and laboratory findings, we diagnosedher cutaneous ulcer as pyoderma gangrenosumdeveloping with exacerbated intestinal Behcet’s disease. Human cutaneous and intestinal lesions were poorly contracted though she received oral prednisolone treat-ment for a month.Because of aggravated abdominalsymptoms with peritoneal irritation, we performed totalcolectomy in November 1989. The resected specimen was histolo gically compatible with intestinal Behcet’s disease showed severe inflammation with deep ulcerations and neutrophil accumulation. Dubbed, pyoderma gangrenosum rapidly improved. This clinicalcourse may suggest the close relationship between pyoderma gangrenosum and intestinal Behcet’s disease.