Background and aimsThis study aimed to investigate the expression of plasma versican and plasma exosomal versican in non-small cell lung cancer (NSCLC) and its correlation with clinicopathological features, and to evaluate its diagnostic performance in NSCLC and its predictive function for NSCLC incidence and metastasis risk.Materials and methodsThere were 110 instances of NSCLC, 42 cases of benign lung disease, and 55 healthy controls from September 2018 to October 2020 at Tongji Hospital Affiliated to Tongji University. Blood was collected and plasma was separated before surgery, and plasma exosomes were extracted by ExoQuick kit. Morphological and molecular phenotype identification of exosomes was performed by transmission electron microscopy, Nanosight particle tracking analysis, and western blotting. Plasma versican and plasma exosomal versican were detected in all subjects to assess their expression levels and diagnostic value in NSCLC. Clinicopathological data were collected to explore correlations between abnormal plasma versican and plasma exosomal versican expression and clinicopathological parameters. Receiver operating characteristic (ROC) curve was used to judge its diagnostic performance in NSCLC, and binary logistic regression analysis was used to predict the risk of NSCLC incidence and metastasis.ResultsPlasma versican and plasma exosomal versican expression in NSCLC patients was significantly upregulated and was significantly higher in T3 + T4 patients compared with T1 + T2 patients (P < 0.05); the levels of plasma versican and plasma exosomal versican were positively correlated with lymph node metastasis, distant metastases (e.g., brain, bone), and mutation(e.g., EGFR,ALK)in NSCLC patients (all P < 0.05). Furthermore, ROC curve analysis showed that plasma versican and plasma exosomal versican had higher AUC values than NSE, CYFRA21-1, and SCC, and better diagnostic performance in NSCLC patients. However, the AUC and diagnostic performances of plasma versican and plasma exosomal versican in advanced-stage NSCLC patients were not shown to be significantly better than CEA. The results of binary logistic regression analysis showed that high levels of plasma exosomal versican had higher predictive value for lung cancer incidence, while high levels of plasma versican had higher predictive value for lung cancer metastasis.ConclusionOur findings showed that plasma versican and plasma exosomal versican might be potential diagnostic markers for NSCLC. High plasma exosomal versican expression can be used as a predictor of NSCLC risk and high plasma versican expression can be used as a predictor of NSCLC metastasis risk.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12931-023-02423-4.