We report a case of subcutaneous splenosis in the abdominal wall of a 23-year-old oligophrenic man. It presented as a well-demarcated 8 x 7 x 5-cm subcutaneous tumor in the left inguinal area closely above the scar after a previous operation for hernia. The lesion simulated clinically a hernia or a tumor due to its large size and location and, additionally, no history could be taken from the patient due to his mental handicap.