Penile squamous cell carcinoma arising from balanitis xerotica obliterans is rarely reported. We describe a 58-year-old man in whom penile squamous cell carcinoma developed after 25 years of observation for balanitis xerotica obliterans. It is important to recognize the possibility of this uncommon complication of balanitis xerotica obliterans, because survival of patients with squamous cell carcinoma depends on early diagnosis and treatment.