Background: Toxoplasma gondii infection in early pregnancy has been associated with significant adverse pregnancy outcomes. Despite being common in the city of Mwanza, its association with spontaneous abortion has never been studied. Here, we report the IgG and IgM seropositivity and histopathological changes of toxoplasmosis among women with spontaneous abortion. Methods: A total of 260 women with spontaneous abortion were enrolled between November 2015 and April 2016 from 4 hospitals in Mwanza city. Specific T. gondii IgG and IgM antibodies were detected from sera by indirect enzyme-linked immunosorbent assay (ELISA) while the conceptus tissues were stained with haematoxylin and eosin to demonstrate histopathological changes. Data were analysed by using Stata version 13. Results: The mean age of the enrolled women was 26±5.9 years. The seropositivity of IgG and IgM antibodies were 144/260 (55.4%; 95% confidence interval [CI], 49–61) and 6/260 (2.3%; 95% CI, 3–8), respectively. IgG seropositivity was significantly high among women in the first trimester (59.1% vs.43.5%; P=.03). Only low gestation age (odds ratio [OR] 1.11; 95% CI, 1.02–1.20; P=.02) and keeping a cat (OR 11.80; 95% CI, 1.32–10.5; P=.03) independently predicted IgG and IgM seropositivity, respectively. Presence of inflammation (OR 1.95; 95% CI, 1.05–3.64; P=.03), calcification (OR 3.28; 95% CI, 1.01–10.63; P=.04), necrosis (OR 2.86; 95% CI, 1.39–5.89; P=.04), and lymphocyte infiltrations (OR 2.24; 95% CI, 1.17–4.24; P=.01) were significantly associated with T. gondii IgG seropositivity. Conclusions: Almost half of women with spontaneous abortion in the city of Mwanza have specific T. gondii IgG antibodies. Placental histopathological changes suggestive of toxoplasmosis were significantly found among IgG seropositive women. This calls for the need to screen these women during antenatal visits in order to institute appropriate measures, such as treatment and counselling, to prevent complications associated T. gondii infection.