Recently, nonsteroidal anti-inflammatory drugs (NSAIDs) have been found to be useful in the chemoprevention of colon cancer. To investigate whether indomethacin, an NSAIDs, induces apoptosis and thus assess the possibility of its application in the chemoprevention of human lung cancer, we have performed MTT assay, TUNEL assay, DAPI staining, and flow cytometric analysis using human lung carcinoma cell line NCI-H1299. Through morphological and biochemical analyses, it was demonstrated that NCI-H1299 cells treated with indomethacin (0.5 mM) exhibit classical apoptotic features. These results suggest that indomethacin induces apoptosis in NCI-H1299 cells and that NSAIDs, including indomethacin, may be a useful tool for the chemoprevention of human lung cancer.