One thousand two hundred pregnant women were examined for Toxoplasma gondii antibody with the objective of identifying the prevalence and risk factors of the disease. By using Sabin-Feldman Dye test, the prevalence of IgG to Toxoplasma gondii was 13.2%. In this study 19 cases (1.6%) were anti-HIV seropositive. Between HIV-seropositive and HIV-seronegative pregnant women, antibody rates to T. gondii were 21.1% and 13.1% respectively, however, the statistical comparison could not be done due to the very few subjects in the former group (n=4). Concerning the risk factors, among those who had no cat in their house, the prevalence of T. gondii antibody were significantly different between under-cooked and properly-cooked meat consumers (19.5%; and 9.6%; odds ratio=2.28, 95% confidence interval). And when under-cooked meat consumers were excluded, the antibody to T. gondii between two groups (having and not-having cat in the house) were also found the significantly different (31.8% and 19.3%; odd ratio=1.96, 95% confidence interval). In conclusion, consuming under-cooked meat and having a cat in the house, both are risk factors of transmission of toxoplasmosis. Further study with more subjects in HIV-infected pregnant women who had antibody to T. gondii, will be helpful for confirmation of the difference with respect to the non HIV-infected group.