Although the periodic health examination was introduced over 80 years ago, it remains a controversy in internal medicine. There have been few data from controlled studies to document the examination's efficacy for adults; nevertheless, its popularity is increasing and health screening has become a multimillion-dollar industry in the United States. Conclusions drawn from poorly designed studies 65 years ago led to the acceptance of periodic examination as a means of detecting disease and reducing mortality. First, physicians associated with life insurance companies and, later, private practitioners began offering these examinations. By promoting the periodic health examination, the medical profession created interest among the general population. The impact of health screening is still unknown today, and well-designed studies are needed to resolve the controversy.