Asthma is a chronic condition of increasing prevalence and high cost to patients, their families, and society. Research into the causes and consequences of asthma has increased during the last few years, but the use of health status measures to help characterize patient outcomes is infrequent. Those studies that have included health status measures have focused on different dimensions of health status, making comparisons across studies difficult. The purpose of this article is to provide information about the selection of health status measures in studies of persons with asthma and to review applications of and make recommendations for health status assessment in asthma research. These recommendations include: use of both generic and specific instruments where appropriate, the development of new asthma-specific measures and rigorous testing of the several new measures that have been reported recently, and the development and inclusion of utility measures in studies of asthma.