Our aim was to evaluate outcomes following a total cavopulmonary connection (TCPC) in patients with preoperatively impaired ventricular function (VF).Of 483 consecutive TCPC patients, 44 (9.1%) had impaired VF (ejection fraction <50%, Group A), and 439 patients had normal VF (ejection fraction >=50%, Group B). We compared the clinical outcomes between the groups.The median age at TCPC was 2.8 (interquartile range 1.9-8.3) years in Group A and 2.3 (1.8-3.5) years in Group B (P = 0.025). An atrioventricular valve (AVV) operation prior to (38.6 vs 27.1%, P < 0.001) and concomitant with (31.8 vs 12.1%, P < 0.001) the TCPC was performed more frequently in Group A. The median intensive care unit stay (7.0 vs 7.0 days, P = 0.737) and 30-day survival (97.7 vs 98.4%, P = 0.737) were not significantly different between groups. Freedom from death, transplantation (P = 0.115) and catheter intervention (P = 0.603) showed no difference between groups. However, freedom from cardiac reoperation was significantly lower in Group A (P < 0.001). VF was resolved in 22 of the 39 (56.4%) survivors in Group A. The recovered patients had a lower incidence of AVV reoperation (0 vs 6, P = 0.002) and pacemaker rhythm (0 vs 5, P = 0.006).In patients planned for TCPC, impaired VF is often associated with AVV regurgitation. TCPC can be performed with low risk and comparable clinical results except for cardiac reoperation in patients with impaired VF when compared to patients with normal VF. Following TCPC, VF recovers in half of the survivors. A competent AVV and sinus rhythm are prerequisites for recovery.