*This paper was read at the South African Medical Congress at Pretoria, July 1948. Statistics of morbidity and mortality in whooping cough are considered to be unsatisfactory in that they underestimate the number of cases and deaths due to the disease. The complications and sequelae of whooping cough include bronchopneumonia, cerebral damage and various psychopathic disorders. In addition there is much loss of school time in child patients and their contacts. In South African Natives, particularly, the predisposition to tuberculosis infection is probably increased. Statistics of the incidence and mortality rates of whooping cough are given for England and Wales and the United States of America. All the figures emphasize the seriousness of the disease in children under five years of age.