BACKGROUND: Solitary pulmonary nodule has received increasing attention in recent years. A couple of lung nodules have been recognized as primary malignant tumors, which leads to an urgent need in enhancing the diagnosis of benign/malignant lung nodules at clinical settings. This study aims to explore the value of the combined detection of cytokines and tumor markers in differencing benign and malignant solitary pulmonary nodules in diagnose. METHODS: With 81 solitary pulmonary nodules cases with a clear diagnosis, the general clinical data, nodule imaging features, pathological diagnosis data, serological index cytokine series and tumor marker expression levels were collected in groups. Both single factor and multi-factors analysis were conducted to screen out the serum influence indexes that can predict the malignant probability of lung nodules, and mean while binary logistic regression analysis was used to construct joint indexes; After receiver operating characteristic curve (ROC) was drawn, the area under the curve and the corresponding sensitivity, specificity and positive of each index predicted value, negative predicted value and accuracy could be calculated with a view to determine the statistical significance of area under the curve (AUC). RESULTS: There are differences in the distribution of malignant solitary pulmonary nodules at different locations, with the highest proportion of the right upper lobe (40.4%). The serum levels of carcinoembryonic antigen (CEA), cytokeratin 19 fragment 21-1 (CYFRA21-1), interleukin-6 (IL-6), interleukin-8 (IL-8) in the malignant nodule group were higher than those in the benign nodule group. Logistic regression analysis suggests that CEA, IL-6 and IL-8 are independent risk factors for predicting malignant nodules. ROC curve analysis shows that the areas under the curve of the individual indicators CEA, IL-6 and IL-8 are 0.642, 0.684 and 0.749. The comparison result of the test efficiency of the area under the curve suggests that CEA+IL-6+IL-8 has a larger area under the curve and higher detection efficiency. CONCLUSIONS CEA, IL-6 and IL-8 are independent risk factors for malignant solitary pulmonary nodules. The combined detection of cytokines and tumor markers has played a role in the differential diagnosis of benign and malignant lung nodules. The diagnostic value of the combined detection of CEA+IL-6+IL-8 is the highest.