The incidence of toxoplasmosis in swineherds from Lima, Peru, was evaluated by serological tests utilizing qualitative and quantitative indirect hemagglutination methods. A total of 310 pigs were sampled, including 155 (males n=77 and females n=78) from highly controlled commercial production situations and 155 (males n=73 and females n=82) reared in poor sanitary conditions. Among the animals reared in good sanitary conditions the frequency of toxoplasmosis reactors was 25.16% ( 18.33-31.99% at 95% confidence ), while the animals reared in poor conditions registered 14.84% (9 .24-20.44% at 95% confidence ). There was al so a significant difference (P<0.05) in the frequency of females reactors among the different commercial herds tested, while the poorly maintained herds showed no deviation (P>0.05). Antibody levels were low in virtually ali the pigs tested. This study documents the presence of swine toxoplasmosis in Lima pig farms with the consequent danger to humans of a contarninated meat supply.