We report herein the case of a patient in whom metastatic colon carcinoma was found within an inguinal hernia sac. According to Lejar's classification, colon carcinomas within inguinal hernias are categorized as intrasaccular- and saccular-type tumors. In our patient, asymptomatic transverse colon carcinoma was the primary lesion, and to the best of our knowledge, this is only the fourth case of such a saccular-type tumor to be reported in the literature. To date, 21 cases of intrasaccular tumors have been reported, and saccular-type tumors are considered to be an even rarer entity, unless the patients have obvious ascites, indicating peritonitis carcinomatosa. Histologic examination of the hernia sac is recommended for male patients of advanced age with an inguinal hernia, especially those who have previously undergone surgery for colorectal carcinoma.