Burkitt's lymphoma (BL) is a high-grade B-cell non-Hodgkin's lymphoma, which can be divided into endemic, sporadic and human immunodeficiency-associated subtypes. The sporadic BL typically presents as an intra-abdominal tumour but that of cutaneous or subcutaneous origin is very uncommon. We present a case of sporadic BL arising from the axillary soft tissue and discuss the CT and MRI findings.