Both patients and the medical profession are quick to embrace new technology, particularly when it may replace an existing surgical procedure. Unfortunately, the rapidity of acceptance is rarely associated with careful evaluation. Laparoscopy is a recent example of such widely embraced technology. Studies of laparoscopy that yielded good comparative data to more traditional methods were slow to accrue. This led to the exposure of its shortcomings through governmental reports and the lay press. To prevent this from happening in thoracoscopy, two types of studies are required so that valid conclusions about the new technology can be drawn. The first is an accounting of the new technology as procedures evolve around it. The data collected in such a study should contain basic information, including the indications for the procedure, how it was performed, procedure length, associated complications, and patient outcome. Such information provides a broad profile of the technology, emphasizing from the outset its potential strengths and weaknesses. The second type of study involves a more detailed concurrent comparison of the specific procedures utilizing this technology to the established traditional methods. Such randomized studies help to firmly establish through scientific process the place of the new technology. The Video-Assisted Thoracic Surgery Study Group was organized in early 1992 to address these concerns. From an initial four surgeons the group has grown to include more than 41 institutions. Currently the group is collecting data in a registry and has established three clinical trials to evaluate video-assisted thoracic surgery.(ABSTRACT TRUNCATED AT 250 WORDS)