Congestive heart failure (CHF) and cognitive impairment are both common problems in old age, associated with significant mortality, impaired quality of life and disability. This study evaluated patients with CHF, admitted to internal medicine and geriatric wards. We identified factors associated with a high risk of in-hospital mortality. Hospitalized CHF subjects with increased risk of in-hospital death present a clinical profile including: very old age, overt cognitive dysfunction, predisposition to falls, dependency, social-family problems, impairment in sphincter control and feeding ability, presence of bedsores, digoxin but not warfarin treatment, hypo-dysproteinemia and hypernatremia and mild renal impairment. We observed that patients admitted to our Internal Medicine Departments, in addition to CHF, present a high grade of complex therapeutic needs and that comorbidity, by itself, does not reflect complexity. Our data support the hypothesis that CHF has different patterns of severity and prognosis in young and in old or very old age groups.