BackgoundNeurosurgical resection is a standard local treatment for lung cancer brain metastases (BMs). This study aims to investigate whether neurosurgical resection provides survival benefit in lung cancer BMs with poor KPS.Materials and methodsThis multicenter retrospective study included 386 lung cancer BMs with pretreatment KPS ≤ 70 among a total of 1177 lung cancer BMs treated at three centers from August 2010 to July 2021. Data analysis was performed from July to September 2022. Inverse probability of treatment weighting (IPTW) and propensity scores matching (PSM) based on propensity scoring were used to minimize bias. The main outcome was overall survival (OS) after diagnosis of BMs. Risk factors of OS were estimated using Cox proportional hazards regression models. All Characteristics were included in the multivariate Cox regression.Results386 patients with pretreatment KPS ≤ 70 were included (age mean [SD], 57.85 [10.36] years; KPS mean [SD], 60.91 [10.11]). Among them, 111 patients received neurosurgical resection, while 275 patients did not. Baseline characteristics were balanced between groups after IPTW or PSM. Neurosurgical resection was associated with significantly better prognosis in unadjusted multivariate COX analysis (hazard ratio [HR]: 0.68, 95% confidence interval [CI]: 0.51–0.91,P= 0.01), and PSM-adjusted multivariate COX analysis (HR: 0.61, 95%CI: 0.39–0.94,P= 0.03), IPTW-adjusted multivariate COX analysis (HR: 0.58, 95%CI: 0.40–0.84,P= 0.004). OS was significantly longer in neurosurgical resection group compared with non-surgical resection group according to unadjusted data (Median OS, surgery vs non-surgery, 14.7 vs 12.5 months,P= 0.01), PSM-adjusted data (median OS, 17.7 vs 12.3 months,P< 0.01) and IPTW-adjusted data (median OS, 17.7 vs 12.5 months,P< 0.01).ConclusionsNeurosurgical resection was associated with improved survival in patients with lung cancer BMs with poor KPS, suggesting that poor KPS is not a contraindication for neurosurgical resection in these patients.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11060-023-04293-8.