Clinical trials are designed to answer specific questions regarding the safety, efficacy and effectiveness of biomedical or behavioral interventions in human subjects. Results from clinical trials have led to many breakthroughs in disease prevention and treatment, and provided evidence to support optimal standards of care into clinical or public health practice. Clinical trials form the evidence base for clinical treatment guidelines. The American Lung Association Asthma Clinical Research Centers network is a multicenter clinical trials' network based in the USA that has significantly contributed to the evidence base for asthma management in both adults and pediatric patients. The purpose of this paper is to provide an overview of how selected Asthma Clinical Research Center studies have affected the treatment and the management of asthma over the past 13 years.