Antigens of Taenia solium can be demonstrated by ELISA technique in stool samples of tapeworm carriers. In order to isolate these immunodiagnostic components from stool, fecal samples of known T. solium carriers were subject to chromatographic purification procedures: immunoaffinity chromatography and a subsequent two-step high performance liquid chromatography yielded a 60-kDa protein that was shown to react in a Western blot with polyclonal anti-T. solium IgG. The protein isolated appeared to be the major antigenic component excreted with the feces of parasite hosts.