Objective: It remains controversial whether non-malignant 'benign' hypertension causes renal dysfunction. The effect of lowering blood pressure on the incidence of renal dysfunction among patients with non-malignant hypertension is not clear. This meta-analysis was conducted to determine whether antihypertensive drug therapy reduces the incidence of renal dysfunction in patients with non-malignant hypertension. Methods: Randomised, controlled trials of antihypertensive drug therapy of more than 1 year duration that reported renal dysfunction as an outcome were identified through MEDLINE search and literature review. A random effects model was used to obtain summary estimates. Results: Ten trials were identified, involving 26 521 individuals and 114 000 person-years. All excluded subjects with advanced baseline renal disease. Definition of renal