Depression has been shown to be a risk factor for the development of coronary artery disease, and also is associated with greater risk of mortality in patients with coronary disease. Treatment of depression may or may not prove to alter depression as a risk factor, but improving the quality of life (QOL) of patients with coronary disease also should be considered a primary outcome. Quality of life is a difficult concept to define and measure. However, recent investigations in patients with coronary disease have examined the relationship of QOL to mortality risk and depression. This article will review the concept and measurement of QOL, discuss studies of factors that predict QOL in patients with coronary artery disease, and focus on the impact of depression on QOL.