We report an additional case of primary adenoid cystic carcinoma of Cowper's gland in an otherwise healthy asymptomatic 66-year-old man. Based on a review of similar lesions presenting in the head and neck, our treatment plan entailed pelvic exenteration followed by radiation therapy. Whether adenoid cystic carcinoma of Cowper's gland behaves as aggressively as it does in the head and neck remains unclear. However, in view of the extensive local invasion in our patient and a previously successful outcome, a combined surgical and radiation approach appears to be the most appropriate therapy.