We report an unusual occurrence of granulocytic sarcoma presenting as an ovarian mass in a 46-year-old woman with a history of dysplastic nevus syndrome. During workup of the ovarian mass, the diagnosis of acute myelogenous leukemia was made. A fine-needle aspirate of the ovarian mass showed granulocytic sarcoma. The patient died of complications of the acute leukemia a short time later. A postmortem examination was performed, which confirmed the nature of the ovarian mass as a granulocytic sarcoma. Material was obtained for flow cytometry, immunohistochemical and histochemical studies, and electron microscopy. Ploidy analysis of the tumor showed it to be diploid with an S phase of 4.8% and a G2 + M ratio of 0.5%. To our knowledge, there is only one previous report of a primary ovarian presentation of granulocytic sarcoma, and only four cases in which granulocytic sarcoma was diagnosed by fine-needle aspiration cytology. The association between dysplastic nevus syndrome and acute myeloid leukemia in this case is discussed with reference to a review of the metachronous association between melanoma and leukemia as described in the literature.