Lung cancer is the second leading cause of cancer death worldwide and is strongly associated with cisplatin resistance. The transcription factor STAT3 is constitutively activated in cancer cells and coordinates critical cellular processes as survival, self-renewal, and inflammation. In several types of cancer, STAT3 controls the development, immunogenicity, and malignant behavior of tumor cells while dictates the responsiveness to radio- and chemotherapy. It is known that STAT3 phosphorylation on Ser727 by mTOR is necessary for its maximal activation, but the crosstalk between STAT3 and mTOR signaling in cisplatin resistance remains elusive. In this study, using a proteomic label-based approach, we reveal important targets and signaling pathways increased and decreased in cisplatin-resistant A549 lung adenocarcinoma cells.