In the last two decades, the interest in eccentric training (ECT) has increased in rehabilitation medicine due to number of specific physiological and biological effects on muscle mass. Based on clinical experience to date, ECT programs can be used not only in healthy people, but also in subjects with varying degrees of physical limitations, including patients with chronic heart failure (CHF). Patients and methods. Twenty-nine patients with mild form of CHF (NYHA I-II); 22 men; 7 women; mean age 63.8 ± 8.9 years, mean body weight 89 ± 17.4 kg. All the patients had 8 weeks of CV-RHB program and the ECT was included as a part of aerobic endurance phase of one training session. Training was performed 3 times/week; duration of one training session was 60min. At baseline and after the end of training period, peak oxygen uptake (VO2peak), peak workload (Wpeak) and muscle power of knee flexors and extensors (using isokinetic dynamometer) were measured for evaluation of overall performance and the setting of training workload. Results. The mean eccentric muscle power increased significantly in both extensors and flexors: in extensors, the peak torque (PT) increased from 114.2 ± 54.6 to 158.6 ± 58.0 Nm (P<0.002) and PT of flexors from 81.1 ± 30.4 to 118.9 ± 29.5 Nm (P<0.003). Compared to concentric muscle power, the studied type of RHB program with ECT seems to be more effective on eccentric muscle power in both knee extensors and flexors. Eight 8 weeks of ECT increased significantly also the mean value of VO2peak/kg (from 20.1 ± 5.1 to 21.6 ± 5.3 ml O2 /kg/min; P<0.05). Conclusion. The results of this preliminary study suggest that ECT can be used safely in patients with CHF (mild grade of the disease) to perform high-load exercise with minimal cardiovascular stress (fairly lower systemic activation, blood pressure, HR, etc.). According to current information from scientific databases, this study is very likely one of the first attempts to include ECT in the rehabilitation of patients with CHF.