Leukemic cells can induce defective expression of soluble factors and change marrow cytokine profile, leading to aberrant cell signaling, cell fixation and cell proliferation in bone marrow. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disorder which accounts for 15% of pediatric ALL. To evaluate the contribution of immunological factors on T-ALL survival, we measured Th1, Th2, Th17 cytokines and soluble HLA-G (sHLA-G) levels in bone marrow from 32 Brazilian children at diagnosis (D0), after induction (D19) and after consolidation (D49) of the chemotherapy phase. Data were analyzed using non-parametric tests, and survival rates were evaluated by Kaplan-Meier method (log-rank test). TNF, IL-10 and IL-6 levels were increased at diagnosis compared to D19 and D49. IL-10 levels < 4.57 pg/mL at diagnosis were associated with increased survival rate, in presence of positive correlation between IL-2 and IL-17 levels. Increased survival rate was also associated with IFN-γ levels < 1.17 pg/mL at D49, with a positive correlation observed between IL-4 and IL-2 as well IL-4 and IL-17 levels. In contrast, worse survival rate was associated with IL-2, IL-4 and IL-10 levels imbalance. In addition, increased sHLA-G levels at diagnosis were associated with increased leukocyte count, a well-known factor for poor prognosis. In conclusion, cytokines and sHLA-G play an essential role in marrow T-ALL microenvironment during chemotherapy, especially the immunosuppressive cytokine IL-10 which can be used as biomarker of disease outcome, being also a potential target for novel T-ALL treatments.