Published articles support the effect of chemotherapy in the immune environment of tumors, including lung carcinomas. The role of CD4 + T-cells is crucial for expansion and accumulation of other antigen-specific immune cells, and the participation of CD8 + cells in tumor killing activity has been confirmed by many studies. However, little is known about the effect of chemotherapy on the healthy lung parenchyma from lung cancer patients, and whether there are differences between the different chemotherapy compounds used to treat this patient population. The aim of our study was to explore the effect of chemotherapy on CD4 + and CD8 + cells in the bronchoalveolar lavage fluid (BALF) of the healthy lung in patients treated with standard chemotherapy regimens. Fifteen patients underwent BAL, in the healthy lung before and after six chemotherapy courses. Platinum-based regimens included vinolerbine (VN) in 6 patients, gemcitabine (GEM) in 4 patients and etoposide (EP) in 5 patients. All patients but one were males and smokers (93%). The median age of patients was 56 years (42-75). No significant difference was noted in the patients' age between the three treated groups. Furthermore, between the three groups, no significant changes in the means of CD4 + and CD8 + cells were noted. However, when we compared the mean CD4 + cells before and after chemotherapy within each group, changes were noted when comparing VN before versus after (p = 0.05), GEM before versus after (p = 0.03), and EP before versus after (p = 0.036). In our pilot study, changes were noted in BALF CD4 + cells for the three most applied regimens at the normal lung parenchyma.