Fibrotic lesions occurring in the corpus cavernosum are usually cases of Peyronie's disease that originate from the tunica albuginea, or they are the fibrotic result of inflammatory processes. The lesion involving the corpus cavernosum, but not tunica albuginea is rare. We present here a case of fibrotic nodule arising in the corpus cavernosum with the sonographic and magnetic resonance imaging features. A 38-year-old man complained a small nodular mass in the left corpus cavernosum at the level of penoscrotal junction without abnormal curvature of the organ. We performed ultrasonography and magnetic resonance imaging to determine exactly what the lesion was. The lesion was removed and it was pathologically found to be a localized fibrotic nodule of the corpus cavernosum with some narrow-channeled vascular structures.