The allocation of professional time of board-certified pediatric cardiologists in 1980 to 1981 was compared with that of pediatric cardiologists in 1967, by use of a similar questionnaire. At both times, the majority of pediatric cardiologists were in a full-time academic or hospital setting. In 1980 to 1981, the number of hours devoted to professional activities was significantly less than during the earlier period, with the reduction being principally in amount of time devoted to research, either clinical or basic, and teaching. This change has implications for manpower and the scientific aspects of pediatric cardiology. An average of 40 physicians enter pediatric cardiology yearly. With the current number of certified pediatric cardiologists, and a modest number of pediatric cardiologists who will leave the field in the next half decade, we project 900 pediatric cardiologists in 1990. A number of factors are discussed that will influence the needs for pediatric cardiologists.