Imatinib mesylate has recently been reported to have clinical activity in the treatment of polycythemia vera (PV), suggesting the involvement of one of the kinases targeted by this inhibitor, including c-Kit and PDGFR. Activating c-Kit mutations have been identified in patients with mastocytosis and other myeloid disorders such as acute myeloid leukemia. Thus, we wanted to analyze the presence of mutations of c-Kit in polycythemia vera patients. We found that 7 out of 20 patients carried missense mutations in the c-Kit gene whereas no sequence variation was detected in 15 healthy controls.