A 55-year-old man had a rare, benign condition of the penis, micaceous and keratotic pseudoepitheliomatous balanitis, for 9 years before developing an aggressive soft tissue sarcoma of the glans. Five months after the appearance of this tumour, the patient died with widespread metastases. The sarcoma was small and superficial and the limited recorded experience suggested that local excision should offer a good prognosis. However, the histology showed poor differentiation and it would seem that this may be the important factor in the management and prognosis of penile sarcoma, as it is in sarcoma at other sites.