Purpose To assess the quality of life (QOL) of elderly lung cancer patients on chemotherapy and explore factors that influence it. Methods A cross-sectional study was conducted with elderly lung cancer patients on chemotherapy at a single cancer center in Chengdu China.Participants completed the Medical Coping Modality Questionnaire, Nutrition Risk Screening 2002, and Distress Thermometer.QOL was assessed using the Function Assessment Cancer Therapy-Lung Module.Multiple linear regression was performed to identify factors independently associated with QOL. Results The 211 lung cancer patients were 65.81 ± 3.61 year old,their total QOL score was94.65 ± 16.51, and their lung cancer-specific module score was 25.64 ± 4.41. Multiple linear regression identified the following factors as associated with QOL, which together explained 47% of observed variance: place of residence, risk of malnutrition, level of psychological distress, and type of coping strategies (adjusted R2 = 0.47, p < 0.001). Conclusion Elderly lung cancer patients on chemotherapy are at risk of poor QOL, which may be improved through timely screening to identify those at risk of malnutrition and through interventions to reduce psychological distress and promote positive coping strategies.