The aim of this study was to demonstrate differences in hospitalization outcomes including length-of-stay (LOS), charges, and mortality in congestive heart failure patients using the Healthcare Cost and Utilization Project dataset. Hospitalizations with International Classification of Diseases, Ninth Revision, clinical modification (ICD-9-CM) codes for congestive heart failure were extracted from a 10% random Healthcare Cost and Utilization Project sample to yield 19,693 hospitalizations between January 1 and December 31, 1997. Mean hospital charges were $11,688 and mean LOS was 5.83 days. The overall in-hospital mortality rate was 4.7%. Both LOS and hospital charges were higher in urban compared with rural hospitals (p< or =0.05). LOS and charges also increased with hospital size (p< or =0.05). Among patient characteristics, patient health status significantly affected LOS, charges, and mortality. Privately insured/health maintenance organization patients had 9% shorter LOS than Medicare patients, and Medicaid patients had 6.6% lower charges and 42% lower mortality than Medicare patients (p< or =0.05). Other significant predictors of study outcome variables included age, gender, race, hospital region, and hospital experience.