It is imperative that comprehensive information on the frequency of fatal sulfonamide reactions be obtained in order that the physician may employ the sulfonamide drugs with a definite knowledge of the dangers involved in their administration. To fill this need, the Pneumonia Control Division of the New York City Department of Health 1 and the Bureau of Vital Records and Statistics cooperated with the New York City Chief Medical Examiner's Office to obtain clinical records for all deaths in New York City during 1941, in which some type of sulfonamide toxicity was a factor. SOURCES OF REPORTS2 The medical examiner's certification provided the greatest proportion of useful records, namely 16 out of 19. Such certification includes a critical examination of the clinical history furnished by the physician or institution and in some cases postmortem examination. Reports received by the health department without the intervention of the medical examiner provided