Chronic penile lymphedema arises from the abnormal retention of lymphatic fluid in the subcutaneous tissues and may be secondary to local and systemic medical conditions such as sexually transmitted diseases, filariasis, malignancy, local radiotherapy, and surgery. This case report aims to consider compulsive masturbation as a possible cause of chronic penile edema. A 40-year-old man was referred to our institute for behavioral disturbance, including compulsive masturbation. Neuropsychiatric evaluation showed moderate mental retardation, mild dysarthria and limb incoordination, anxiety, depressed mood, and impulse dyscontrol. Brain MRI pointed out diffuse white matter lesions. Urogenital examination revealed an uncircumcised penis with non-tender edema of the shaft and prepuce with areas of lichenification. Since the most common local and systemic causes of edema were excluded, chronic penile edema due to compulsive masturbation was diagnosed and the compulsive behavior treated with an antidepressant and low-dose neuroleptics. Compulsive masturbation should be taken into account when counselling patients with penile edema.