Groin pain in the lower abdomen but including the ilioinguinal region is frequent after inguinal hernia operations, but the integrity of the nerves in this region, including the genitofemoral nerve (GFN), has not been investigated. We studied GFN motor conduction time to the cremasteric muscle (CM), the CM electromyogram (EMG), and the CM reflex in 30 patients with unilateral inguinal hernia who underwent herniorrhaphy and in 26 similar patients who had no surgical intervention. Among the 30 patients undergoing herniorrhaphy, 14 (47%) showed motor involvement of the GFN, whereas 6 of the 26 (23%) patients not treated surgically had involvement of the GFN. These findings indicate that subclinical motor involvement of the GFN can be demonstrated by electrophysiological methods and is common after inguinal herniorrhaphy. Based on patient complaints, the herniated mass may also be responsible for motor involvement of the GFN in some patients before surgery.