Using data from the National Center for Health Statistics, I conducted an in-depth analysis of numbers of thoracic and cardiovascular operations from 1979 to 1984. This is the first full 5 year period since the inception of International Classification of Diseases, Ninth Revision, Clinical Modification codes, and the findings delineate the present status of thoracic and cardiovascular surgery in the United States. During the study period there was a 34% increase in total numbers of thoracic and cardiovascular operations. Since 1970 there has been a total increase in numbers of thoracic and cardiovascular operations of 150%. In 1983 thoracic and cardiovascular surgeons performed 191,000 coronary artery bypasses. This operation is the most common thoracic and cardiovascular procedure and has become the nineteenth most common operation now performed in this country. Pacemaker placement, revision, or removal (190,000) is the second most common thoracic and cardiovascular operation and the country's twentieth. The twenty most common thoracic and cardiovascular operations constitute 87% of all thoracic and cardiovascular operations. In 1983 thoracic and cardiovascular operations represented 3% of all operations completed in this country. These figures represent the dynamics of thoracic and cardiovascular surgical practice. They demonstrate that numbers of thoracic and cardiovascular operations have consistently increased over the past 15 years. However, this increase is almost entirely due to the advent of coronary artery bypass.