We aimed to investigate changes in serum concentrations of the cytokines interleukin (IL)-2 and interferon (IFN)-gamma during the clinical course of active tuberculosis, to establish the presence of cellular immunity before and after treatment. Blood samples were taken from 18 patients with active tuberculosis before and 2 months after therapy; IL-2 and IFN-gamma concentrations were evaluated. The mean serum IL-2 concentration before therapy was 164.5 pg/ml (range 12 - 980 pg/ml) and the concentration 2 months after therapy was 92.11 pg/ml (range 1 - 490 pg/ml). The mean serum IFN-gamma concentrations were 10.83 pg/ml (range 1 - 22.2 pg/ml) and 4.64 pg/ml (range 1 - 28.5 pg/ml), respectively. The decrease in concentrations of both cytokines after therapy was statistically significant. Further studies investigating the benefits of adding cytokines to drug treatment for tuberculosis are needed.