We investigated in 306 patients, mean age 57 ± 10 years, with diabetes mellitus (202 patients) or hypertension (179 patients) whether microalbuminuria was a significant independent risk factor for the development of new stroke or new myocardial infarction (MI) or death. At 39-month follow-up, new stroke or new MI or death developed in 44 of 111 patients (40%) with microalbuminuria and in 38 of 195 patients (19%) without microalbuminuria (p = 0.0001). Stepwise Cox regression analysis showed that significant independent predictors of the time to development of new stroke or new MI or death were (1) diabetes (risk ratio = 1.76), (2) left ventricular (LV) mass index (risk ratio = 1.020 for each 1 g/m<sup>2</sup> increase), (3) prior stroke (risk ratio = 5.39), and (4) prior MI (risk ratio = 3.29). Microalbuminuria was not a significant independent predictor of new stroke or new MI or death, but LV mass index, diabetes mellitus, prior stroke, and prior MI were significant independent predictors.