Background: Most of the patients with interstitial lung disease (ILD) complicated with lung cancer (ILD-LC) showed non-specific clinical manifestations. This study is to explore the incidence of lung cancer concealed in the end-stage of interstitial lung disease (LC-CES-ILD). Methods: A total of 154 cases of lung transplantation from March 2017 to December 2018 were studied retrospectively, of which 7 cases were found to be LC-CES-ILD. Serum tumor biomarkers were examined. HE and immunohistochemical staining were performed for the tumor tissue after the operation. Lung cancer (LC) drive gene was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The percentage of male patients with idiopathic pulmonary fibrosis (IPF) was 44.81%. The expression of all tumor biomarkers was significantly increased in 6 patients with LC-CES-ILD. After operation, apparent destruction of lung tissue structure was observed in 7 patients, and honeycomb appearance could be seen in some areas. After HE staining, 4 cases of acinar type and 2 cases of mucinous adenocarcinoma were found. The results of molecular pathology showed that only one case of mucinous adenocarcinoma had KRAS mutation, and no mutation of LC co-driving gene was found in the rest of the cases. Conclusions: It is necessary to detect the lung tissue of patients with end-stage ILD, which were probably correlated with the occurrence of LC concealed, before lung transplantation.