Renal fossa heterotopic splenic tissue is characteristically asymptomatic and is usually an incidental finding that has been reported to mimic renal or adrenal tumors. However, symptoms related directly to the splenic tissue do occur. We present an unique case with simultaneous occurrence of an accessory spleen and splenosis which were diagnosed following intentional radiological investigations conducted to evaluate flank pain which was probably related to the presence of the heterotopic spleens. CT complemented by isotopic liver-spleen scan is the radiological modality of choice in the diagnosis of renal fossa splenosis. However, MRI may significantly contribute to the evaluation by accurate delineation of blood supply and surgical separation planes.