The aim of this study was to investigate the ratio of the transcription factors T-bet/GATA-3 in patients with allergic asthma. Forty-seven individuals with allergic asthma and 47 healthy control individuals provided 5 ml of anticoagulated peripheral venous blood. Lymphocytes in peripheral blood were isolated by Ficoll and treated with phytohemagglutinin (PHA) at a final concentration of 100 mg/l for 48 h. Interferon-γ (IFN-γ) and interleukin-4 (IL-4) levels were detected using an enzyme-linked immunosorbent assay (ELISA), and the mRNA levels of both T-bet and GATA-3 were detected using reverse transcription polymerase chain reaction (RT-PCR). IFN-γ levels in the lymphocytes of asthmatic patients were lower than those of the control group (P<0.05) and were positively correlated with the ratio of T-bet/GATA-3. By contrast, IL-4 levels were significantly higher in asthmatic patients than in the control group (P<0.01) and were negatively correlated with the ratio of T-bet/GATA-3. In conclusion, the ratio of T-bet/GATA-3 can be used as an objective indicator of immune imbalance in patients with allergic asthma.