Objective To investigate the levels and clinical significance of cold-inducible RNA-binding protein (CIRBP) and mucin 5AC (MUC5AC) in serum and bronchoalveolar lavage fluid (BALF) of patients with interstitial lung disease (ILD). Methods A total of 63 ILD patients who were hospitalized in the Department of Pulmonary and Critical Care Medicine, The First Hospital of Lanzhou University from January 2022 to February 2024 were collected, including 22 patients with idiopathic pulmonary fibrosis (IPF), 20 patients with connective tissue disease-related interstitial lung disease (CTD-ILD), and 21 patients with other types of ILD. Thirty healthy individuals with matching demographic characteristics during the same time period were selected as the healthy group. Enzyme linked immunosorbent assay was used to detect the levels of CIRBP and MUC5AC in serum of healthy group, the levels of CIRBP and MUC5AC in serum and BLAF of ILD patients. The levels of CIRBP and MUC5AC in serum were compared between the healthy group and the ILD group, and the levels of CIRBP and MUC5AC in serum and BALF were compared among the patients with different types of ILD. The correlations were analyzed between the levels of CIRBP and MUC5AC and the lung function, blood gas analysis, and 6-minute walk distance (6MWD) in the patients with different types of ILD. The receiver operating characteristic curve was drawn according to the levels of CIRBP and MUC5AC in serum. The optimal cut-off value, sensitivity and specificity of serum CIRBP and MUC5AC for diagnosis of ILD were determined. Results The serum CIRBP level in the three groups of ILD patients was higher than that of the healthy group (P<0.01), but there was no significant difference in the serum CIRBP level among the three groups of ILD patients (P>0.05). There was no significant difference in serum MUC5AC levels between the three groups of ILD patients and the healthy group, as well as among the three groups of ILD patients (P>0.05). There was no significant difference in the levels of CIRBP and MUC5AC in BALF among the three groups of ILD patients (P>0.05). CIRBP in BALF of the IPF patients was negatively correlated with 6MWD, while CIRBP in serum of the CTD-ILD patients was negatively correlated with partial pressure of oxygen and arterial oxygen saturation. CIRBP in serum of other ILD patients was negatively correlated with total lung capacity as a percentage of predicted value (TLC%pred), forced vital capacity as a percentage of predicted value (FVC%pred), diffusion capacity of carbon monoxide of lung as a percentage of predicted value (DLCO%pred), and 6MWD, while CIRBP in BALF was negatively correlated with DLCO%pred. The MUC5AC in BALF of IPF patients was negatively correlated with DLCO%pred, while the MUC5AC in BALF of CTD-ILD patients was negatively correlated with TLC%pred, DLCO%pred, and 6MWD. The serum MUC5AC in other ILD patients was negatively correlated with FVC%pred, DLCO% pred, and 6MWD. The sensitivity was 77.6%, and the specificity was 96.7% for diagnosing ILD with serum CIRBP. Sensitivity was 55.1%, and specificity was 76.7% for diagnosing ILD with serum MUC5AC. The combination of the two indicators resulted in a sensitivity of 87.8% and a specificity of 86.7% for the diagnosis of ILD. Conclusion The high expression levels of CIRBP and MUC5AC have certain diagnostic efficacy and disease assessment effects on ILD, and may serve as potential biomarkers for ILD.