Two hundred and eighty-seven patients referred to the National Research Institute for Occupational Diseases with suspected pneumoconiosis are recorded. The patients are classified according to the type of dust to which they were exposed, and by occupation or industry. Radiological evidence of pneumoconiosis according to ILO/UICC classification is the only acceptable basis for compensation at present, and the number of patients so diagnosed is also given. None of these figures show the true distribution and incidence of pneumoconiosis as a form of occupational disease on the Witwatersrand. They only indicate the presence of pneumoconiosis not associated with mining and reflect a wide range of occupations.