One-hundred and ninety-one men with Type 2 (non-insulin-dependent) diabetes mellitus, participants in the Whitehall Survey, were followed for 15 years. Age-adjusted all-cause and ischaemic heart disease (IHD) mortality rates were significantly increased in the diabetic men. Of four putative risk factors for IHD ascertained in the survey (plasma cholesterol, systolic blood pressure, cigarette smoking, body mass index) only blood pressure was a significant predictor in univariate Cox regression analysis. A review of comparable studies revealed lack of consistency in the association of these risk factors (derived from studies in non-diabetic populations) and mortality in individuals with Type 2 diabetes. Given the absence of clinical trial data, risk factor intervention in Type 2 diabetes is currently based upon inference derived from studies in non-diabetic subjects.