OBJECTIVE. This study was conducted to summarize the clinical and radiologic presentations including pertinent imaging features of granulocytic sarcoma, a rare extramedullary tumor of acute myeloid leukemia, in 11 adult patients. CONCLUSION. In patients in our study, the clinical and radiologic manifestations of granulocytic sarcoma were variable and occurred most commonly as disease progression in acute myeloid leukemia (73% of the patients). Granulocytic sarcoma lesions were multiple soft-tissue masses with variable enhancement, recurring in nearly 50% of patients at different sites and points of time during the course of the disease. Lesions in the central nervous system, subcutaneous tissues, and genitourinary system accounted for nearly 52% of all lesions. In general, granulocytic sarcoma masses were isodense to muscle on CT scans, and isointense and hyperintense (mild to moderate) on T1- and T2-weighted MR images, respectively. The presence of peripheral rim enhancement with hypodense or hypointense centers on T1-weighted images may, however, mimic an abscess.