A 67-year-old woman suffered from an ovarian carcinoma with lymph nodes metastasis. During 3 years, she was treated with alkylating agents (Melphalan). At the end of therapy, no recurrence was observed. Two years later, she developed concomitantly pyoderma gangrenosum and acute myelomonocytic leukaemia. Death occurred rapidly. The association between pyoderma gangrenosum and acute leukaemia is discussed in the light of 16 cases previously reported in the literature. In this case, an induction of leukaemia by cytostatic drugs seems likely. The authors conclude that pyoderma gangrenosum may be considered as a cutaneous signs of acute leukaemia.