The Diabetes Intervention Study (DIS) is a prospective population-based multicentre trial of newly detected cases of non-insulin-dependent diabetes mellitus (NIDDM). This report analyses the risk factors for subsequent coronary heart disease and all-cause death during the 11-year follow-up. The prognostic significance of the categories of the NIDDM Policy Group was validated with respect to the incidence of coronary heart disease and mortality. At baseline 1139 subjects, aged 30-55 years at the time of diabetes detection and classified as diet controlled after a 6-week screening phase, were included. Of the patients 112 (15.2%) suffered from myocardial infarction, 197 (19.82%) of 994 had died. The odds ratio for all-cause mortality compared to the general population for males at the age of 36-45 years was 5.1 and for females 7.0. In multivariate analysis age, blood pressure and smoking were independent risk factors for myocardial infarction and male sex, age, blood pressure, triglycerides, postprandial blood glucose and smoking for death, respectively. The categories of the NIDDM Policy Group target parameters for blood glucose, triglycerides and blood pressure were significant predictors of both CHD and death. Thus, it appears that in NIDDM good control of blood glucose, blood pressure and triglycerides is associated with a lower incidence of coronary heart disease and death rate respectively.