A 33-year-old woman developed a bullous PG precursing a chronic myelomonocytic leukemia (CMML) complicated by life-threatening, disseminated, intravascular coagulation after administration of systemic corticosteroids in combination with immunosuppressant and antibiotic agents. Although the association between PG and leukemia, as well as the coincidence of disseminated intravascular coagulation (DIC) and leukemia, is well known, a premonitoring effect of PG in combination with DIC preceding the diagnosis of chronic myelomonocytic leukemia in the same patient has not been reported recently.