Hereditary haemolytic anaemias, in particular, thalassaemia and the haemoglobinopathies, have been found to be a significant cause of hereditary haemolytic disease in West Malaysia. Theoretically 1 in 2500 marriages are between heterozygotes for beta-thalassaemia and 1 in 10,000 children can be expected to have thalassaemia major. An approach to the prevention of this disease would be public education and identification of carriers: to develop some approach to the identification and genetic counselling of beta-thalassaemia trait.