A positive family history is an established risk factor for ischaemic heart disease, but the size of the contribution relative to classical risks is open to debate. The literature suggests that inherited factors are important in the development of premature ischaemic heart disease, but decline in importance with age. A polymorphism in the angiotensin-converting-enzyme gene was the first new genetic factor thought to contribute independently and significantly to cardiovascular risk. However, more recent large prospective studies have indicated that its contribution is smaller than was originally thought. Interventions should continue to be targeted at the reduction of important environmental factors, such as smoking cigarettes.