Body composition and systemic inflammation/nutrition have been identified as important clinical factors in cancer patients. The modified advanced lung cancer inflammation index (mALI), which combines body composition and systemic inflammation/nutrition, is defined as appendicular skeletal muscle index × serum albumin/neutrophil-lymphocyte ratio. This retrospective study aimed to investigate associations between preoperative mALI and surgical outcomes in non-small cell lung cancer (NSCLC) patients. We examined 665 patients with resectable stage I-III NSCLC who underwent pulmonary resection. Patients were divided into low-mALI (n = 168) and high-mALI (n = 497) based on the lower quartile. Kaplan-Meier curves and Cox regression analysis were used to assess the prognostic value of mALI. We then performed 1:1 propensity score matching (PSM) for high- and low-mALI to further investigate impacts on survival. Overall survival (OS) and recurrence-free survival (RFS) were both significantly poorer in the low-mALI group than in the high-mALI group (58.2% vs. 79.6%, P < 0.001; 48.8% vs. 66.7%, P < 0.001, respectively). Multivariate analysis revealed low-mALI as an independent predictor of OS (hazard ratio [HR], 2.116; 95% confidence interval (CI) 1.458-3.070; P < 0.001) and RFS (HR, 1.634; 95% CI 1.210-2.207; P = 0.001). After PSM, low-mALI remained as an independent predictor of OS (HR, 2.446; 95% CI 1.263-4.738; P = 0.008) and RFS (HR 1.835; 95% CI 1.074-3.137; P = 0.026). Preoperative mALI appears to offer an independent predictor of poor surgical outcomes as a simple, routinely available, and inexpensive biomarker in patients with resectable NSCLC.