We herein report a rare case of acantholytic acanthoma in a 42-year-old male patient. The tumour was located on the skin of the amputated right lower limb stump and the patient was using prosthesis. The physical effects of the prosthesis may be considered in the histogenesis of this entity, although convincing data does not exist. To the best our knowledge acantholytic acanthoma in this localization has not been previously reported.