Curcumin has been found to exhibit anticancer activity and certain studies have shown that curcumin triggers the apoptosis of human A549 lung adenocarcinoma cells. However, the mechanism underlying curcumin‑mediated apoptosis is not completely understood. The present study was designed to investigate the effect of curcumin on the induction of apoptosis and apoptosis‑related factors in human A549 lung adenocarcinoma cells. Treatment of A549 cells with curcumin caused a concentration‑dependent inhibition of cell growth and an increase in apoptosis, as confirmed by THE MTT assay, flow cytometry and morphology analysis. Curcumin‑treatment of A549 cells induced a loss of the mitochondrial membrane potential and increased cytosolic cytochrome c. Furthermore, curcumin‑induced apoptosis was accompanied by changes in intracellular oxidative stress‑related enzymes, including decreased intracellular reactive oxygen species levels, increased superoxide dismutase and decreased malondialdehyde and 4‑hydroxynonenal. In addition, induction of apoptosis was also accompanied by phosphorylation and activation of mitogen‑activated protein kinase signaling pathway factors c‑Jun N‑terminal kinase, p38 and extracellular signal-regulated kinase.