Ambroxol is a mucolytic agent frequently used in the treatment of chronic bronchitis. It has been reported, following clinical and in-vitro studies, that ambroxol exhibits an anti-inflammatory action. This capability was investigated by activating bronchoalveolar lavage cells and peripheral blood mononuclear cells in-vitro to elicit the release of tumor necrosis factor alpha, interleukin-2 and interferon gamma, whilst simultaneously exposing them to varying pharmacological concentrations of ambroxol (10, 1, and 0.1 microM). After 24 h it was observed that the isolated tissue-culture supernatants showed a dose-dependent reduction in the concentration of the tested cytokines; 10 microM (12 to 37% reduction) and 1 microM to (6 to 27% reduction). At 0.1 microM, a significant reduction could only be observed in the release of interleukin-2 by bronchoalveolar lavage cells. These results demonstrate, that ambroxol exhibits anti-inflammatory actions in concentrations achievable in vivo.