Sweet's syndrome with malignancy or acute neutrophilic dermatosis (AND) is an unusual cutaneous disorder seen most commonly in association with acute myelogenous leukemia. A large majority of patients with AND and malignancy have neoplasms of hematopoietic, plasma cell or lymphoid nature. The patient reported here had myelofibrosis, chronic myelogenous leukemia and Sweet's syndrome. The individual lesions responded to intralesional interferon-alpha 2, which has not to our knowledge been reported previously. This result, however, was not as great as the response of AND to intralesional steroid injections.