Blood circulating endothelial cells and circulating hematopoietic progenitor cells (CPCs) are two cell populations that are thought to play important role in angiogenesis. In the present study, we investigated the role of CPCs in patients with brain tumors. We prospectively studied 19 brain tumor patients. Ten healthy individuals were used as controls. Variables that were analyzed included age, sex, Ki-67 index, symptom duration, tumor location, tumor size and preoperative Karnofsky performance status score (KPS). CPCs were determined as CD45(dim)/CD34+/CD133+ in the peripheral blood. Twelve patients had glioblastoma (GBM), 1 patient had a grade II glioma and 6 patients had meningioma. Brain tumor patients had significantly higher CPC levels compared to healthy volunteers. Patients with gliomas had significantly higher CPC levels than patients with meningiomas. In GBM patients no correlation was found between CPC levels and sex, age, Ki-67 index, tumor location, size and KPS. Patients with CPC levels lower than 1,743 cells/ml had a higher progression-free survival but the difference was not statistically significant. Glioma patients had higher CPC levels compared to patients with meningiomas. Larger studies are obviously needed to verify the role of CPC levels in patients with brain tumors.