Objective:To analyze the relationship between T lymphocytes and blood rheology test results in patients with non-small cell lung cancer (NSCLC) and their chemotherapy outcomes.Methods:A total of 108 patients with NSCLC who received treatment in the Affiliated Hospital of Shaanxi University of Chinese Medicine between May 2021 and May 2023 were included in the observation group. A total of 108 participants who concurrently underwent physical examinations were included in the control group. T lymphocyte subsets and blood rheology indices were tested in both groups. In the observation group, T lymphocyte subsets and blood rheology indices were compared before and after chemotherapy. Additionally, T lymphocyte subsets and blood rheology indices were compared between the chemotherapy-effective group and the chemotherapy-ineffective group. The risk factors for ineffective chemotherapy in patients with NSCLC were analyzed.Results:The CD 4+ and CD 4+/CD 8+ levels in the observation group were significantly lower than those in the control group, and whole blood viscosity in high-, medium-, and low-shear rates as well as CD 8+ level in the observation group were significantly higher than those in the control group ( t = 22.64, 32.29, 28.72, 24.53, 28.29, 18.72, all P < 0.001). After chemotherapy, whole blood viscosity at high-, medium-, and low-shear rates, as well as CD 8+ levels, significantly decreased in the observation group compared with pre-chemotherapy levels. Conversely, CD 4+ and CD 4+/CD 8+ levels significantly increased ( t = 16.85, 27.15, 19.15, 16.03, 21.10, 13.50, all P < 0.001). In the chemotherapy-ineffective group, whole blood viscosity in high-, medium-, and low-shear rates as well as CD 8+ level were (6.08 ± 0.67) mPa·s, (10.45 ± 1.09) mPa·s, (15.59 ± 1.61) mPa·s, (25.58 ± 2.61)%, respectively. These values were significantly higher than those in the chemotherapy-effective group [(4.86 ± 0.51) mPa·s, (8.12 ± 0.91) mPa·s, (11.86 ± 1.28) mPa·s, (23.14 ± 2.41)%, t = 10.24, 11.36, 11.52, 4.65, all P < 0.001]. CD 4+ and CD 4+/CD 8+ levels in the chemotherapy-ineffective group were (37.82 ± 3.96)% and (1.48 ± 0.15), respectively, which were significantly lower than those in the chemotherapy-effective group [(40.05 ± 4.14)%, (1.73 ± 0.19), t = 2.56, 6.55, both P < 0.001]. Multivariate analysis revealed that whole blood viscosity at high-, medium-, and low-shear rates, as well as CD 8+ levels, were independent risk factors for ineffective chemotherapy in patients with NSCLC ( OR = 1.425, 1.697, 1.705, 1.719, all P < 0.05). Conversely, CD 4+ and CD 4+/CD 8+ levels were identified as protective factors against NSCLC (both P < 0.05). Conclusion:Patients with NSCLC have obvious T lymphocyte subset disorders and hemorrheological abnormalities. T lymphocyte subsets and hemorrheological indicators are factors that affect the effectiveness of chemotherapy and can be used to evaluate the effectiveness of chemotherapy in patients with NSCLC.