A serological survey of Toxoplasma gondii infection among slaughtered pigs in the largest slaughterhouse located in Taoyuan County of northwestern Taiwan was conducted using the latex agglutination (LA) test during 1998. The overall seroprevalence of T. gondii infection was 28.8% (32/111) with LA titers of 1:32 (6, 18.8%), 1:64 (10, 31.2%), 1:128 (9, 28.1%), 1:256 (6, 18.8%), and 1:512 (1, 3.1%). No significant difference (P > 0.05) in seroprevalence between male (28.6%, 20/70) and female (29.7%, 12/41) slaughtered pigs was observed. A decreasing trend in the seroprevalence among slaughtered pigs examined in the same slaughterhouse was observed because of a lower seroprevalence (P < 0.05) than that (44.4%, 128/288) previously reported about 10 yr ago using the LA test. Nevertheless, it is important to avoid eating raw or undercooked pork in order to prevent the acquisition of T. gondii infection among people in Taiwan.