The benefits and advantages of automated systems for cardiopulmonary exercise testing are well appreciated. Overenthusiasm and overconfidence in computer "black box" generated information, however, has resulted in inadequate attention to important issues related to quality control. The objective of this article is to provide basic and practical information related to equipment, methodology, conduct of the test, and quality control that will help assure clinically reliable results. The authors elaborate on the most widely applied methodologies and current criteria and guidelines of exercise testing.