Following infection with Trichinella spiralis, the host elicits a strong immune response that causes rapid expulsion of parasites, a reduction in reproductive capacity of the remaining parasites a reduction in the number of larvae recovered from host muscles, and impairment of the mobility of worms in the intestines. The need to identify the antigens that evoke such responses is twofold: (1) to develop immunodiagnostic tools; and (2) to understand the basis of protective immunity. In this review, Yuzo Takahashi describes the antigenic profiles of T. spiralis, emphasizing immunocytochemical findings.