The paper describes examination methods used in diagnosing toxoplasmosis in humans and animals with special attention paid to serology techniques: Sabin-Feldman test, indirect fluorescent antibody test, Enzyme-Linked Immunosorbent Assay (ELISA), Enzyme-Linked Fluorescent Assay (ELFA), direct agglutination test. New trends in research on toxoplasmosis using molecular biology methods are also presented.