Abstract OBJECTIVES Although post-cardiotomy extracorporeal life support (PC-ECLS) is a potentially life-saving resource for patients with cardiopulmonary failure after cardiac surgery, adverse outcomes have been reported even in successfully weaned patients. The goal of this study was to assess outcome in patients weaned from PC-ECLS. METHODS Of 573 consecutive patients who received PC-ECLS at a single centre between 2000 and 2019, 478 patients were included in a retrospective analysis. Successful weaning was defined as survival >24 h after extracorporeal life support (ECLS) explantation. Mortality of patients on ECLS, as well as in-hospital mortality of weaned patients, was assessed. A binary logistic regression model with backward elimination was used to identify predictors for in-hospital mortality after successful ECLS explantation. RESULTS Of 478 included patients, 120 patients (25.1%) died on ECLS or within 24 h after ECLS explantation. A total of 358 patients were successfully separated from ECLS and survived for >24 h (n = 352 weaned, n = 3 transitioned to durable left ventricular assist device and n = 3 transitioned to a heart transplant). A total of 35.5% of patients who were successfully weaned from ECLS did not survive until hospital discharge. In-hospital deaths of the whole cohort were 51.7% (247/478 patients). For patients who survived to discharge (231/478 patients, 48.3%), survival was 87% after 1 year and 68.9% after 5 years. CONCLUSIONS In-hospital mortality of patients requiring PC-ECLS is high even in case of successful weaning. Longer ECLS duration, older age, female gender and low preoperative glomerular filtration rate were risk factors for in-hospital mortality after ECLS weaning. Survival of patients discharged after PC-ECLS was encouraging.