Lung cancer is one of the most common malignant tumours. Patients are frequently at risk of frailty as lung cancer progresses. The meta-analysis aims to explore the impact of frailty on the long-term prognosis and the incidence of short-term chemotherapy toxicity in patients with lung cancer. This study was designed adhered to the criteria of Cochrane Handbook for Systematic Reviews. Systematic searches were performed on PubMed, Embase, Web of Science and Cochrane Library databases for relevant studies until December 2022. The outcome measures were overall survival, progression-free survival, chemotherapy toxicity and all-cause mortality. We then performed sensitivity analyses, subgroup analyses and evidence quality. This meta-analysis was performed using Review Manager V.5.4 software. Of the included studies, six were retrospective and five were prospective. There was a statistically significant difference between the frail and non-frail groups in overall survival (HR 2.27, 95% CI 1.24 to 4.15, p=0.008), all-cause mortality (HR 1.63, 95% CI 1.00 to 2.65, p=0.05) and chemotherapy toxicity (OR 3.73, 95% CI 1.99 to 7.00, p<0.0001). We conducted a sensitivity analysis, and the result was stable. The study revealed frail group had shorter survival and experienced more severe adverse effects than the non-frail group. Frailty affects the long-term prognosis and the incidence of short-term chemotherapy toxicity of patients with lung cancer. Consequently, medical professionals should focus on frailty screening in patients with lung cancer and implement active intervention measures. PROSPERO registration number is CRD42023398606.

All data relevant to the study are included in the article or uploaded as online supplemental information.