Gossypiboma or textiloma is the result of a foreign-body reaction to extraneous material, usually a surgical sponge that was accidentally retained within the body. The diagnosis of a retained surgical sponge is often delayed due to its infrequent occurrence and protean appearances. The purpose of this pictorial review is to define the common sonographic and CT features of gossypiboma. A retrospective review of sonographic and CT images of 6 surgically proven cases of retained surgical sponges was undertaken.