Introduction: The presence of disseminated tumor cells (DTC) in the bone marrow (BM) of breast cancer patients is associated with poor prognosis. Several studies demonstrated that tumor cell dissemination may occur in gynecologic cancer and affect clinical outcome. The aim of our study was to evaluate the incidence of DTC and to assess their prognostic significance in patients with gynecologic malignancies. Methods: Bone marrow aspirates from 377 patients with primary ovarian (112), endometrial (141), cervical (102), and vulvar cancer (22) undergoing surgery at the Department of Gynecology and Obstetrics, University Hospital, Tuebingen, Germany between November 2001 and November 2007, were included into the study. Disseminated tumor cells were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3 and by cytomorphology. Results: Disseminated tumor cells were detected in 19% of BM aspirates from patients with gynecological malignancies. Incidences of DTC in ovarian, endometrial, cervical, and vulvar cancer were 25%, 16%, 19%, and 5%, respectively. For patients with ovarian and endometrial cancer, no correlation with established clinicopathological factors was observed. In case of cervical cancer, BM positivity was correlated with International Federation of Gynecology and Obstetrics stage, tumor size, and nodal involvement. Bone marrow positivity of ovarian cancer patients was correlated with significantly shorter disease-free survival (P = 0.035). For other tumor entities, no association between BM status and clinical outcome could be observed. Conclusions: We conclude that up to 25% of patients with loco-regionally restricted gynecologic malignancies present with DTC at the time of diagnosis. For ovarian cancer patients, BM status affected clinical outcome.