Toxoplasmosis is a disease with various clinical findings caused by Toxoplasma gondii. Primer infection is generally asymptomatic in immunocompetent adults but rarely symptoms observed may include fever, malaise, sore throat, headache, maculopapular rash, and lymphadenopathy. The prevalence of T. gondii is depending on geographic diversity, age, race, diet, and lifestyle. In this study, we investigated the distribution of anti-T. gondii IgG and IgM antibodies in patients suspected with toxoplasmosis referred to Erciyes University Medical Faculty Parasitology laboratory between July 2009 - June 2011 retrospectively. It was investigated anti-T. gondii antibodies with the Enzyme-Linked Immunosorbent Assay (ELISA) and Indirect Fluorescence Antibody Technique (IFAT) in serum specimens of 336(21.3%) males and 1245 (78.7%) females, totally 1581 subjects. It was determined that 456 (28.8%) patients were IgG positive, 8 (0.5%) patients were IgM positive and 79 (5%) patients were both IgG and IgM positive. IgG-avidity values were investigated in 535 (%33.8) patients having anti-T. gondii IgG antibody positive. It was found that 466(87.1%) patients had high IgG avidity, 13 (2.4%) low avidity and 56(10.5%) of them were in an equivocal range.