Interferon-gamma release assay (IGRA) was introduced as an in vitro test detecting T. gondii infection. Few studies have investigated the potential role of cell immunity in diagnosis of toxoplasmosis. IGRA accurately distinguished infected from uninfected individuals after in vitro stimulatoion with T. gondii antigens, even during the first days of life. IGRA is an easy-operation and low-cost method to measure cell mediated immunity against T. gondii. These results underline the importance of evaluating cellular immunity for early diagnosis of toxoplasmosis. ELISA-based IGRA holds the potential to become a useful diagnostic tool for early detection of T. gondii.