Background: We investigated whether curcumin and genistein affect the MUC5AC mucin production from human airway epithelial cells that is induced by phorbol 12-myristate 13-acetate (PMA) or tumor necrosis factor-${alpha}$ (TNF-${alpha}$). Methods: Confluent NCI-H292 cells were pretreated with each agent for 30 min and then stimulated with PMA or TNF-${alpha}$ for 24 hours. MUC5AC mucin production was measured by an ELISA. Results: (1) Curcumin dose-dependently inhibited the production of MUC5AC mucin that was induced by PMA or TNF-${alpha}$; (2) Genistein inhibited PMA-induced MUC5AC mucin production. However, it did not decrease TNF-${alpha}$-induced MUC5AC mucin production. Conclusion: These results suggest that curcumin and genistein inhibit the production of airway mucin induced by PMA.