The aim of this study was to determine the prevalence of toxoplasma antibodies among pregnant women in Cali, Colombia. In 2005, 955 pregnant women were tested for IgG and IgM antibodies and sociodemographic information was collected. Their average age was 25.1 years, overall IgG seroprevalence 45.8% (95% CI: 41.8%, 48.2%), IgM 2.8% (95% CI: 1.5%, 3.6%). Seroprevalence increased significantly with age, 39.0% in 14 to 19 years to 55.3% in 30 to 39 years (P = 0.001). There was a significant trend toward a higher seroprevalence in the lower socioeconomic strata (SES) (low: 49.0%, high: 29%, P = 0.004). The increase in seroprevalence by age was more significant in the lower socioeconomic strata (P = 0.002). Our results suggest a higher prevalence when compared with those of the national 1980 (33-37.6%) survey. In contrast to reports from other regions of the world, Cali has not seen a decrease in T. gondii seroprevalence over the past 25 years.