A 66-year-old man with aneurysm of the abdominal aorta presented with a soft groin mass. The mass, being reducible, had gradually enlarged for the last one-and-a-half years. Diagnosed as having an inguinal hernia, he underwent hernia surgery, together with Y-grafting for aneurysm. Surgical exploration revealed that the mass was lipoma that arose from the spermatic cord. The tumor was covered with a thin fibrous capsule and completely excised. Spermatic cord lipoma should therefore be included in the differential diagnosis of inguinal hernia.