BACKGROUND: Toxoplasma gondii is an obligate intracellular protozoan organism that infects both birds and mammals. Human infections are particularly serious if they occur during pregnancy and may result in abortion or congenitally acquired disorders which primarily affect the central nervous system. This study assessed seroprevalence of Toxoplasma gondii infection and associated risk factors among pregnant women at Debre Tabor, Northwest Ethiopia. METHODS: An institution based cross-sectional study was conducted from February to May, 2013. A total of 263 pregnant women who came to Debre Tabor public health facilities for antenatal care were selected and included in the study. The venous blood serum was tested using toxolatex agglutination test. Data on socio-demographic and potential risk factors were collected using structured questionnaire through face-to-face interview. Data were entered and analyzed using SPSS version 20.0. Both bivariate and multivariate analyses were carried out to identify associations between dependent and independent variables. RESULTS: Of 263 pregnant women included in the study, 180 (68.4%, 95% CI: 63.1-71.4%) were found to be seropositive for anti-toxoplasma antibody. Multivariable analysis showed; age group ≥ 36 years (Adjusted Odds Ratio [AOR] = 3.56; 95% CI: 1.01-12.5), cannot read and write (AOR = 4.77; 95% CI: 1.01-30.3), and cat ownership (AOR = 3.36; 95% CI: 1.39-8.12) were significantly associated with seropositivity of T.gondii infection. CONCLUSIONS: Seroprevalence of T.gondii infection in Debre Tabor town was high. Age, educational status and presence of cats in home were identified as factors associated with T.gondii infection. Education of pregnant women about the transmission and prevention methods of this infection through health extension and in antenatal care clinics is important. Besides, studies on incidence of toxoplasmosis in newborns and infants are recommended