We report a case of idiopathic elephantiasis of penis. A 41-year-old man was refered to our hospital with a painful penile swelling and severe miction pain. He had no particular past or familial history, and had never been to tropical or semitropical region. Physical examination showed a prominent swelling and flection of his penis. Magnetic resonance imaging revealed a significant thickening of the penile skin and subcutaneous tissue. Due to the difficulty of voiding, an urethral catheter was placed. The penile skin biopsy showed no malignancy. Under the diagnosis of penile elephantiasis, the resection of abnormal penile skin and penile plasty with the split skin graft from his thigh was performed. Histopathological findings showed nonspecific inflammation. The skin graft was successfully adapted. He could urinate smoothly without pain after the urethral catheter was removed. There has been no recurrence 6 months after the operation. He recovered normal micturition and sexual function.