Toxoplasma gondii (T. gondii) is an obligate intracellular parasite distributed worldwide. Serological tests investigating antibodies specific to T. gondii are widely used in diagnosis. The aim of this study was to evaluate the results of anti-T. gondii IgG, anti-T. gondii IgM, and anti-T. gondii IgG avidity tests, which were sent to the Serology Laboratory of Trakya University Health Center for Medical Research and Practice, retrospectively. Anti-T. gondii IgM, anti-T. gondii IgG, and anti-T. gondii IgG avidity tests were studied by enzyme-linked fluorescent assay or electrochemiluminescence immunoassay method between January 2012 and December 2021. The test results were evaluated retrospectively from laboratory records. Of 18,659 serum samples were studied for anti-T. gondii IgG, 5,127 (27.5%) samples were positive, whereas 721 (3.4%) of 21,108 samples were positive for anti-T. gondii IgM. Of the 593 serum samples tested for IgG avidity, 206 (34.7%) samples had low avidity, 118 (19.9%) had borderline, and 269 (45.4%) had high avidity. Our study, compatible with other studies, showed that seropositivity is high in our region, which is not negligible. Especially in women of reproductive age population, T. gondii should be considered in suspected clinical cases.