OBJECTIVE To investigate the effects of high frequency oscillatory ventilation (HFOV) and HFOV combined with pulmonary surfactant (PS) treatment on lung tissue after steam inhalation injury in rabbits. METHODS Twenty-four New Zealand rabbits were randomly and equally divided into three groups after reproduction of severe steam inhalation injury, each n=8. Then they were ventilated by conventional mechanical ventilation (CMV), HFOV or HFOV+PS (100 mg/kg, drip via trachea), respectively. Animals were sacrificed after 4 hours, then the middle lobe in the right lung were excised for histological sections and the degree of injury was assessed. RESULTS Histological injury in rabbits of HFOV groups were less serious than the CMV group. Among three groups, histological injury in rabbits of CMV group was most evident and least in the HFOV+PS group. It was also found that in CMV group showed the highest score of histological injury (3.71+/-0.43), and the lowest was found in HFOV+PS group (2.08+/-0.28), and that of HFOV group was 2.87+/-0.26. Comparison between whichever two of the three groups showed statistical significance (P<0.05 or P<0.01). CONCLUSIONS HFOV can alleviate pulmonary edema and infiltration of inflammation cells, and it is shown that HFOV combined with exogenous PS gives the best outcome.