Recent evidence suggests that non-insulin-dependent diabetes mellitus (NIDDM) and cardiovascular disease, rather than being related as underlying disease and complication, share common genetic and environmental antecedents, that is, they "spring from the same soil." Fetal and early-life nutritional deficiencies appear to predispose persons to both NIDDM and cardiovascular disease in later life. The insulin resistance syndrome, including abdominal obesity, may constitute the intermediate link between fetal and early-life nutritional deficiency and later disease. The insulin resistance syndrome includes insulin resistance, hyperinsulinemia, abdominal obesity, dyslipidemia with high triglyceride and low high-density lipoprotein cholesterol levels, and hypertension. Each element of the insulin resistance syndrome has been firmly established as a risk factor for development of diabetes. In addition, most of these elements are also well-recognized cardiovascular risk factors, although the weight of evidence now suggests that hyperinsulinemia itself is not. This last point is significant because of concern that aggressive insulinization of diabetic patients, which has been proved to reduce microvascular complications, might paradoxically increase the risk for large-vessel atherosclerosis. Available clinical trials suggest that this fear is unwarranted, but definitive trials are needed to resolve this important clinical question.