The number of heart valve replacement procedures has increased over the last four decades, with >200,000 done worldwide every year. Various valve substitutes are available, and are broadly divided into biological and mechanical prostheses. Choice is dictated by multiple factors, including longevity of the valve substitute as well as patient and surgeon preference. In general, mechanical valves are used in the younger age group and require lifelong anticoagulation. Biological valves are used in older age groups and have a limited lifespan compared to mechanical valves. The design of prosthetic heart valves continues to evolve, with improved haemodynamics, longevity and durability. Mortality and morbidity associated with heart valve surgery is low. Infrequent but major complications of valve replacement include haemorrhage, thromboembolism and infection.