An outbreak of trichinellosis caused by wild boar meat occurred in the Iruela (Jaen) in southern Spain in February 1996. Thirty-five people were diagnosed on the basis of epidemiologic data, but only 24 patients agreed to participate in this study. Twenty-three (96%) had symptoms suggestive of trichinellosis. Immunofluorescent and Western blot test results for trichinellosis were positive in 18 persons, and 15 had circulating Trichinella spiralis antigens. These findings suggest that results of tests for circulating antigens in conjunction with clinical presentation are useful for the diagnosis of trichinellosis.