The complex interactions between cancer and host cells are far from being fully elucidated. Assessment of Th1/Th2/Th3/Tr1 balance is an interesting approach to explain immunological disturbances in lymphomas. The aim of our study was to assess mRNA for pro- and anti-inflammatory cytokines in T-cells in 20 children with Hodgkin- and non-Hodgkin lymphomas. CD4+ and CD8+ cells were isolated from whole peripheral blood and four different cytokine mRNA levels (IFN-gamma, IL-10, IL-4, TGF-beta) were determined by real-time PCR technique. Comparing to the control group, we found lower expression of mRNA for IFN-gamma in CD4+ cells at the time of lymphoma diagnosis. It may be one of the pathogenetic mechanisms of impaired immunity in these patients.