No major genes responsible for insulin resistance have yet been identified. CD36 is a multifunctional receptor, which plays a part in mediating intracellular signalling as well as in taking up biologically active substances such as long-chain fatty acids. We looked for insulin resistance in genetic CD36 deficiency, which is common in Asian and African populations. The euglycaemic hyperinsulinaemic clamp technique showed insulin resistance in the five CD36-deficient people tested. We conclude that CD36 could be responsible for insulin resistance.