The serological prevalence of Toxoplasma gondii was determined, using indirect haemagglutination assay, in the sera of 169 cats. Classification by age, sex, alimentary, hunting and roaming habits was made in conjunction with the number of cats living in each house. An important prevalence was detected (19.5%) from 1 year of age and statistical significance was found in those animals that had predatory habits or lived in groups.