Cumulative findings have demonstrated that the dysregulation of tumor suppressor genes may be implicated in cigarette smoke-induced carcinogenesis. Activating enhancer-binding protein 2 (AP-2) is a eukaryotic transcriptional factor that plays a significant role in embryonic development and tumorigenesis. The vertebrate AP-2 family consists of AP-2α, AP-2β, AP-2γ, AP-2δ and AP-2ε. Previous studies have suggested that cigarette smoking disrupts AP-2 regulation. In the present study, we investigated the effects of cigarette smoke condensate (CSC) on AP-2α expression in human lung cancer cell lines (NCI-H1299, NCI-H446 and A549), as well as the potential mechanisms involved. Using RT-qPCR, we found that CSC decreased AP-2α expression by suppressing its transcription in human lung cancer cell lines, particularly in p53-deficient NCI-H1299 cells. Western blotting and luciferase assays were implemented and we found that the restoration of p53 expression rescued the NCI-H1299 cells from CSC-induced AP-2α loss, while the silencing of p53 resulted in increased AP-2α loss induced by CSC, suggesting an antagonizing role of p53 in the regulation of AP-2α by CSC. Our results indicate that AP-2α downregulation may be involved in smoke-induced lung carcinogenesis.