Objectives: This study aimed to analyze and evaluate serum insulin-like growth factor-binding protein 2 (IGFBP2) levels as a new biomarker of severe malnutrition in patients with advanced lung cancer.Design and methods: This prospective study involved 59 patients with advanced lung cancer. We detected serum IGFBP2 level by using enzyme-linked immunosorbent assay and analyzed its relationship to clinical characteristics, nutritional status, Glasgow prognostic score (GPS), and survival. Serum albumin and C-reactive protein (CRP) levels were measured, and nutritional status was assessed using Patient-Generated Subjective Global Assessment (PG-SGA). The best cutoff point value for serum IGFBP2 level was established using receiver operating characteristic analysis. Kaplan-Meier method was utilized to analyze the survival curves.Results: Serum IGFBP2 levels were elevated in patients with advanced lung cancer and severe malnutrition. The best cutoff value for serum IGFBP2 level was determined at 363 ng/ml, which could diagnose severe malnutrition with 73.3% sensitivity and 70.5% specificity and was found to be related to albumin, CRP, and GPS. Patients whose serum IGFBP2 levels were higher than 363 ng/ml had poor survival outcome.Conclusion: This study demonstrates the remarkably association between higher serum level of IGFBP2 and severe malnutrition, albumin, CRP, GPS, and survival. Hence, serum IGFBP2 level can be used as a potential biomarker for diagnosis of severe malnutrition in patients with advanced lung cancer.