Planned efforts for the improvement of child health and reduction of mortality among children depend to a considerable extent on accurate information concerning the causes of disease and death. An automatic method for measuring the size and character of the problem at local, state and national levels is provided by legal requirements for certification of all deaths. Any conclusions derived from study of death certificates, however, are influenced strongly by the accuracy of the diagnoses. In most medical schools, unfortunately, the importance of proper medical certification of causes of death is given all too little emphasis. The article below was written at the request of the undersigned to indicate some of the problems in connection with medical certification and some of the methods by which it may be improved. Obviously, this is a matter which needs close attention by every practitioner of medicine.