BACKGROUND: Congestive heart failure (CHF) is an increasingly common condition associated with significant hospital resource utilization. Initiating better disease management at the time of initial hospital admission has the potential to reduce readmissions. OBJECTIVE: To evaluate the impact of a multifaceted quality improvement program on 12-month hospital utilization in patients admitted to hospital with CHF. DESIGN: Prospective longitudinal study comparing baseline and intervention cohorts. PARTICIPANTS: All consecutive patients with CHF discharged alive from 3 metropolitan hospitals during the baseline (October 1, 2000 to April 17, 2001) and intervention (February 15, 2002 to August 31, 2002) study periods. Active prospective case-finding identified 220 baseline and 235 intervention participants; full data was available on 197 baseline and 219 intervention participants. INTERVENTIONS: Education and performance feedback for hospital and primary care practitioners; clinical decision support tools; individualized, guideline-based treatment plans; patient education and self-management support; and improved hospital-community integration. MEASUREMENTS: Twelve-month all-cause hospital readmission, 12-month mortality, readmission-free survival, heart failure-specific readmission, and total hospital days over 12 months. RESULTS: Intervention patients had a higher rate of all-cause readmission (odds ratio [OR] = 1.65; 95% confidence interval [CI] = 1.10-2.46) but a trend to reduction in mortality (OR = 0.68; 95% CI = 0.44-1.07). There was no difference in frequency of hospitalizations per year, number of hospital days, or the composite outcome of death or readmission. CONCLUSIONS: The intervention improved care processes and may have reduced mortality, but at the cost of higher readmission rates. Better understanding of intervention components, intensity, and targeting may optimize the effectiveness of disease management programs.