A seroepidemiological survey of cats for Toxoplasma antibody revealed a high infection rate. No significant difference was detected between males and females or between rural and urban areas, although acute infection seems to be more prevalent in males and in rural areas as revealed by the high titres of the dye test. Toxoplasmosis in cats, as revealed by serologic surveys, seems to prevail more during the warm rather than the hot season of the year being favoured by milder temperature and higher relative humidity and rainfall in the former season. Futhermore, it was concluded that infection rate with Toxoplasma increases with the age of the host. Toxoplasma antibody in the young age groups is to a great extent of maternal origin. Study of the relationship of Toxoplasma to Isospora showed no cross immunity. They follow a reversed pattern with increasing age of the host. Data also shows the high specificity of dye testing for detection of Toxoplasma antibody. Feeding experiments show that a relatively high percentage of cats shed oocysts in their faeces. Not only seropositive but also seronegative cats excrete oocysts, though at a lower rate in the latter case. The majority of cats shedding oocysts are those with either low positive titres or seronegative cats.