This study was designed to identify proteins interacting with GLRX5 in small cell lung cancer cells using co-immunoprecipitation (Co-IP) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). DMS114 human small cell lung cancer cells were transfected with a GLRX5 overexpression construct or the corresponding negative control vector. GLRX5-associated protein complexes were immunoprecipitated from cell lysates and subsequently subjected to mass spectrometric analysis for protein identification. The proteomic data were analyzed to characterize candidate GLRX5-interacting proteins and to explore the potential molecular network associated with GLRX5 in small cell lung cancer. This dataset provides proteomic evidence for investigating the protein-protein interaction landscape of GLRX5 and its potential role in SCLC progression.