BACKGROUND: Cardiogenic pulmonary edema increases nonspecific airway responsiveness in humans and animals. Increased extravascular lung water from overt pulmonary edema to subclinical interstitial edema is a common finding in patients with chronic renal failure. Several studies carried out to assess pulmonary function disturbances in this condition have documented a reduction in forced expiratory volume that usually reverses after hemodialysis, suggesting airway edema as the underlying mechanism. This interstitial edema may also lead to nonspecific bronchial hyperre- sponsiveness. We hypothesized that patients with chronic renal failure may present nonspecific bronchial hyperresponsiveness due to subclinical interstitial pulmonary edema. METHODS: We studied 18 chronic renal failure undergoing regular hemodialysis 3 times a week (New York Heart Association Class II) without concomittent disease. These patients were checked pulmonary function test and metacholine provocation test before hemodialysis and same procedure was repeated if responsive, after hemodialysis. RESULTS: 1) 12 out of 18 patients before hemodialysis were reactive in metacholine provocation test (66.7%) before hemodialysis. This airway hyperresponsiveness were decreased after hemodialysis. 2) Pulmonary function was improved after hemodialysis and change in FEV1 was correlated with change in weight(r= -0.62, p<0.01). 3) There was a close correlation between log PD20 and FEF25, which is one of the variables of the peripheral airways(r=0.58, p<0.05). CONCLUSION: We speculated interstitial pulmonary edema may play a significant role in bronchial hyperresponsiveness and lung function impaired in patients with chronic renal failure.