OBJECTIVE To compare cardiopulmonary exercise capacity of patients undergoing primary total cavopulmonary connection (TCPC) with those undergoing TCPC after a prior bidirectional Glenn (BDG). METHODS Out of 42 patients in this study, 24 had undergone primary TCPC while 18 had undergone staged TCPC. The peak oxygen consumption (O(2) peak), O(2) pulse, chronotropic index, and other exercise parameters were studied. RESULTS There were no significant differences in O(2) peak (940 ± 538 vs. 1010 ± 417 mL/min, p=0.42) and O(2) pulse (5.76 ± 3.52 vs. 6.85 ± 2.95) of patients undergoing staged TCPC versus primary TCPC, respectively; however, chronotropic index (0.43 ± 0.23 vs. 0.30 ± 017, p=0.047) was significantly different. Exercise tolerance was the same in fenestrated versus nonfenestrated TCPC groups and age at TCPC less than or more than 7 years. However, O(2) peak and O(2) pulse of patients with extracardiac TCPC was better than patients with lateral tunnel TCPC (p values 0.05, 0.04 and respectively). Some parameters of exercise tolerance of patients with antegrade pulmonary blood flow (APBF) interrupted at the time of BDG were better than those with APBF open. CONCLUSIONS There were no differences in the exercise parameters of patients undergoing a staged versus a primary TCPC, fenestrated versus nonfenestrated TCPC, and age at surgery less than or more than 7 years. Exercise parameters were better in the extracardiac conduit group versus lateral tunnel TCPC groups. Patients who had a TCPC after prior interruption of APBF had better exercise parameters.