Syphilitic gumma involving the penis is a rare manifestation of tertiary syphilis. Only seventeen cases have been reported in the literature. It can mimic other diagnoses such as penile carcinoma. We report a case of a 56 year old male that had been sexually abstinent for over 10 years and presenting with a 4 cm painful penile lesion with clinically palpable bilateral inguinal nodes with no prior history of sexually transmitted diseases (STDs). A positron emission tomography-computed tomography scan identified the penile mass as being hypermetabolic and suspicious for penile carcinoma. Several inguinal and pelvic lymph nodes were also found to be suspicious for penile carcinoma. A penile biopsy was proposed and declined by the patient as he opted for a partial penectomy. The surgery was performed for diagnostic and palliative purposes. Histopathological studies revealed the presence of polymorphous, granulomatous, epitheloid inflammatory infiltrate with giant cells. Additional microbiologic testing confirmed the diagnosis of tertiary syphilis, presenting as gummatous syphillis associated with neurosyphilis. The patient was treated with intravenous penicillin and had adequate clinical clinical and serologic 12 months following treatment. Gummatous syphillis is a rare entity, but should be considered in the differential diagnosis of a penile lesion. To rule out this possibility, a biopsy should always be performed prior to invasive penis surgery.