BACKGROUND: The main clinical manifestation of the nerve entrapment syndrome in the inguinal region is chronic and spontaneous pain of the scrotal region and proximal ventro-medial thigh region. Few reports have discussed the anatomic background of this kind of pain with special reference to skin innervation.OBJECTIVE: To study the features of clinical anatomy in entrapment of nerve for providing anatomic basis for preventing and treating entrapment of nerves in the inguinal region.DESIGN: Observational study based on cadavers.SETTING: Anatomical department in a university.MATERIALS: Fifty halves of twenty-five adult male cadavers that were routinely embalmed and fixed by the Anatomical Department of Dali University from January 1998 to December 2000.METHODS: Cutaneous nerves in the inguinal region in 50 halves of 25adult male cadavers were observed, measured and drawn.tionship of the genital branch of the genitofemoral nerve to the inguinal canal.RESULTS: In addition to cutaneous branches originating from the iliohypogastric nerve in 3 of 50 cases(6% ), cutaneous branches from the ilioinguinal nerve were found in the inguinal region in 45 of 50 halves(90% ),cutaneous nerves from the genital branch of genitofemoral nerve were in 21 of 50 halves(42% ), the unions of the ilioinguinal nerve and genital branch of the genitofemoral nerve were in 6 of 50 sides(12% ), and branches from the femoral branch of the genitofemoral nerve were in 4 of 50 sides(8% ) . The genital branch of genitofemoral nerve and the ilioinguinal nerve united at three the canal(1 case). The cutaneous branches of the genital branch were found to perforating the transversus abdominis and the obliquus internus abdominis via the border between the ligament and the aponeurosis of obliquus externus abring after being united with the ilioinguinal nerve.CONCLUSION: The courses of cutaneous nerves in the inguinal region vary considerably, and the anatomic variations of these nerves may be a principal cause for nerve entrapment.