Granulocytic sarcoma (GS) occurs in patients with chronic myeloproliferative disorders as well as in patients with acute myeloid leukemia (AML). These tumorous masses can occur anywhere in the body and have to be differentiated from lymphoma, carcinoma or infectious processes. We report the results of fine-needle aspiration cytology (FNAC) in 26 patients with GS. Seventeen patients suffered from AML and 9 from chronic myeloid leukemia (CML) blast crisis. In 5 patients with AML, GS was the initial presentation of hematological malignancy, in the remaining 21 patients, FNAC confirmed relapse of AML or extramedullary blast crisis of CML. In 8 patients, GS was located in the skin, in 17 in the lymph node and in another patient in the spinal canal. This study demonstrates the clinical utility and diagnostic accuracy of FNAC in the evaluation of GS from multiple sites.