Natural history studies in heart failure have shown that increases in left ventricular (LV) volume and LV mass are directly related to future deterioration in LV performance and a less favorable clinical course. Despite the recognized importance of remodeling in heart failure, very little is known about the basic mechanisms that lead to cardiac remodeling. In this review, we will summarize recent clinical and experimental studies that highlight the importance of the remodeling process during the progression of heart failure. The intent of this review is to provide an integrated view of the mechanisms that contribute to LV remodeling at the cellular level, the myocardial level, and the level of the chamber.