Aim: The aim of this study was to investigate the histological changes in lung of rats exposed to cigarette smoke and effects of caffeic acid phenetyl ester (CAPE) on these changes.

Materials and method: For this purpose, 21 male Wistar rats were divided into three groups. Animals in Group I were used as control. Rats in Group II were exposed to cigarette smoke and rats in Group III were exposed to cigarette smoke and injected daily with CAPE. At the end of the 60-days experimental period, all rats were killed by decapitation. Following routine histological procedures, lung tissue specimens were examined under a light microscope.

Results: In our study, quite intensive inflamatuar cell infiltration on wall of terminal bronchiol and interalveolar connective tissue was observed in the lung specimens of rats exposed to cigarette smoke. Additionally, it was seen that numerous macrophage containing hemosiderin pigment, vacuolization and congestion areas. In rats exposed to cigarette smoke and injected with CAPE, cigarette smoke-induced histological changes were partially disappeared.

Conclusion: it was observed that exposure of cigarette smoke caused histological damage in lung tissue of rats and this damage was partially prevented by administration of CAPE.