Objective: To investigate the distribution of toxoplasma gondii antibodies retrospectively among the first trimestr antenatal population in Trakya region. Material and methods: This study retrospectively analyzes seroprevalance of toxoplasma gondii IgM and IgG antibodies in the sera of 1646 first trimester pregnancies attended to the Obstetrics & gynecology Antenatal Care . For this purpose IgM, IgG and if necessary, IgG avidity results were evaluated. Besides, hepatitis B surface antigen (HBsAg), human inmmunodeficieny virus type 1 and 2 antibodies (Anti HIV), cytomegalovirus (AntiCMV) IgG and IgM antibodies, hepatitis C antibody (AntiHCV), rubella (antirubella) IgM and IgG antibodies and "venereal disease research laboratory" (VDRL) results evaluated in the same period were also investigated. Results: Although the status of seroprevalance is not known in 313 (19%) women, 876 pregnant women (65.71%) were IgG and IgM seronegative, 426 (31.95%) were IgG seropositivite, 13 (0.97%) were IgM positivite and 18 (1.35%) were both IgG and IgM seropositivite. On the other hand, 13 of 18 patients with both IgG and IgM seropositivity showed high avidity but avidity could not be evaluated in 4 patients. HBsAg positivity was found in 3% (47/1526), AntiHCV positivity in 0.8% (12/1474), VDRL in 0.4% (5/1056), rubella IgM antibody in 0.7% (9/1254), rubella IgG antibody in 76.6% (940/1227), according to the other serologic tests. AntiCMV IgM antibody was positive in 17 (17/1284, 1.3%) and IgG was positive in 1027 (1027/1279, 80.3%) patients. Conclusion: As well as toxoplasma exposure rate in the pregnant women from Trakya region of Turkey is high (%30), nearly half of first trimester women were found seronegative. Screening during the first trimester would be appropriate, particularly for women who are under risk of infection.