Background: We conducted a secondary analysis to (1) compare changes in mood disorders and quality of life (QOL) among 4 groups of patients with heart failure in a home-based exercise program who had varying degrees of change in their exercise capacity and (2) determine whether there was an association between exercise capacity, mood disorders, and QOL. Methods: Seventy-one patients were divided into 4 groups based on changes in exercise capacity from baseline to 6 months: group 1showed improvements of greater than 10% (n = 19), group 2 showed improvements of 10% or less (n = 16), group 3 showed reductions of 10% or less (n = 9), and group 4 showed reductions of greater than 10% (n = 27). Results: Over time, patients in all 4 groups demonstrated significantly lower levels of depression and hostility (P amp;lt; .001) and higher levels of physical and overall quality of life (P = .046). Group differences over time were noted in anxiety (P = .009), depression (P = .015), physical quality of life (P amp;lt; .001), and overall quality of life (P = .002). Greater improvement in exercise capacity was strongly associated with lower depression scores (r = -0.49, P = .01). Conclusions: An improvement in exercise capacity with exercise training was associated with a decrease in depression and anxiety and an increase in QOL in patients with heart failure.