Insulin resistance confers increased susceptibility to NIDDM, atherosclerotic cardiovascular disease, ovarian hyperandrogenism, and possibly hypertension. Insulin resistance is largely inherited, in rare cases as a monogenic disorder or more commonly as a complex trait. The search for insulin resistance genes relies mainly on two complementary approaches: 1) positional cloning using random DNA markers present throughout the genome; and 2) the analysis of specific candidate genes. This report briefly summarizes the candidate gene approach to insulin resistance. Progress related to the analysis of genes encoding molecules that participate in insulin action is reviewed. In addition, the spectrum of potential genetic defects that might contribute to insulin resistance, both at the level of the target cell and secondarily (e.g., obesity genes), is discussed.