Cytochalasin H (CyH) has been shown to exhibit promising anticancer activities against various types of cancers; however, the underlying mechanisms remain unknown. In a previous study, we isolated CyH from the mangrove‑derived endophytic fungus Phomopsis sp. in Zhanjiang, China. In the present study, we further explored the effect of CyH on apoptosis and migration in the human lung adenocarcinoma cell line A549. Cell Counting kit‑8 (CCK‑8) assay was used to observe the effects of CyH on the growth of A549 cells. The cell cycle and apoptosis were determined using flow cytometry. The effect of CyH on cell migration was observed by scratch wound healing and chamber migration assays. Western blotting was used to detect the expression of apoptosis‑ and metastasis‑associated proteins. Our results showed that CyH exhibited cytotoxicity to A549 cells. The treatment of CyH arrested A549 cells at the G2/M phase. Furthermore, sub‑G1 peaks and fragmented DNA ladders were observed, and the mitochondrial transmembrane potential was also decreased in CyH‑treated A549 cells. CyH significantly increased Bax, P53, and cleaved caspase‑3 (17 kDa) protein expression and decreased Bcl‑xL, Bcl‑2, and full‑length caspase‑3 (35 kDa) protein expression, resulting in an increased ratio of the pro‑apoptosis/anti‑apoptosis proteins Bax/Bcl‑2. Additionally, CyH treatment inhibited the migration ability of A549 cells in a dose‑dependent manner. Taken together, our results suggest that CyH may be a potential chemopreventive drug for the treatment of lung cancer.