Professor David Weatherall is the outstanding British clinician scientist of his generation. He is an accomplished pioneering researcher in molecular genetics, haematology, pathology and clinical medicine. The results of David Weatherall laboratory and clinical research on thalassaemias has helped to explain the molecular pathophysiology and causes of phenotypic variability of these disorders. These findings have provided the basis for ante-natal diagnosis and genetic counselling aimed at preventing these abnormalities and have improved the clinical management of inherited blood disorders. He has drawn global attention to the challenge of caring for the increasing numbers of thalassaemia sufferers who now survive beyond childhood. In a broader sense, his discoveries have demonstrated how understanding of molecular genetics can be applied to design practical strategies for disease prevention, control and alleviation.