Objective To compare the features of the parameters of cardiopulmonary exercise testing (CPET) between the elderly patients with chronic left heart failure (LHF) and those with chronic right heart failure (RHF). Methods A prospective study was carried out on 25 elderly patients with chronic LHF [20 males, aged (60.2±4.7) years] and 25 elderly patients with chronic RHF [(19 males, aged (61.3±5.7) years]. Those patients with pulmonary diseases, neuromuscular diseases and/or anemia were excluded. Valuables of CPET were compared between the 2 groups. Results There was no significant difference in the gender, age, BMI and New York Heart Association (NYHA) class between the 2 groups. Echocardiography indicated that left ventricular end-diastolic diameter was significantly larger in the LHF group than in the RHF group [(66.1±9.0) vs (40.4±5.4)mm, P＜0.001], left ventricular ejection fraction was obviously lower in the former than in the latter group [(32.5±11.9)% vs (65.8±8.1)%, P＜0.001]. LHF group had remarkably larger peak VO2 [(1056.6±340.5) vs (750.9±269.1)ml/min], higher peak VO2/kg [(15.1±2.7) vs (11.0±3.2)ml/(min·kg)] and percentage of predicted value of peak VO2 [(52±13)% vs (39±11)%] when compared with those of RHF group (P＜0.05). Peak VO2/HR was significantly lower in the RHF group than in the LHF group [(6.3±2.2) vs (8.5±3.0)ml/(min·beat), P＝0.016]. Compared with LHF group, VO2/WR slope was obviously decreased in RHF group [(5.1±1.1) vs (6.4±1.8)ml/(min·W), P＝0.014], and VE/VCO2 slope was significantly higher [(34.7±8.2) vs (49.5±12.6), P＜0.001]. Conclusion Compared with LHF, cardiopulmonary functions are worse and VE/VCO2 slope is higher in the patients with RHF, even when having similar NYHA class.