Background: Stratification of the severity of heart failure has major prognostic and therapeutic implications. Aims: To prospectively compare different methods of assessment of functional capacity in patients with chronic heart failure (CHF). Methods and results: We studied 143 patients (78 male and 65 female) with CHF aged less than 70 years (mean 57.3 years). Functional assessment was made clinically according to NYHA classification and according to the Goldman Activity Scale Classification (GASC). Cardiovascular performance was measured by peak O2 consumption (pVO2) and anaerobic threshold (AT) at cardiopulmonary exercise test and by the distance walked during a 6-min walk test (6-MWT). Clinical scales resulted significantly related. Peak VO2 and AT showed a mild relation with distance covered at 6-MWT (r