The diagnosis of retained sponges and towels a year or more after surgery is often very difficult. We describe the computed tomographic (CT) findings in 4 patients with this complication; 2 cases of retained sponges and 2 cases of retained towels. While the CT appearance of the retained sponges was not specific, the particular appearance of the retained towels had not been previously described. This appearance is characteristic enough to suggest the correct diagnosis before reoperation.