Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used in adult cardiac surgery to support patients with postcardiotomy cardiogenic shock (PCCS), difficulty weaning from cardiopulmonary bypass (CPB), and severe perioperative respiratory or biventricular failure. Despite guideline development by international societies, ECMO in this setting remains associated with high mortality and complication rates. Objective: To describe indications, management strategies, and short-term outcomes of ECMO use in adult cardiac surgery patients and to identify factors associated with in-hospital mortality. Methods: We conducted a single-center retrospective cohort study of adult patients (≥18 years) who received venoarterial ECMO (VA-ECMO) in the context of cardiac surgery between January 2019 and December 2023. Indications, ECMO configuration, duration of support, complications, and outcomes were collected. Primary outcome was in-hospital mortality; secondary outcomes included ECMO weaning success, major complications, and ICU length of stay. Multivariable logistic regression was used to determine predictors of mortality. Results: Among 3,850 adult cardiac surgery procedures, 112 patients (2.9%) required perioperative VA-ECMO. The main indications were failure to wean from CPB (57%), refractory PCCS in the ICU (29%), and perioperative cardiac arrest (14%). Overall in-hospital mortality was 54%. Successful decannulation occurred in 62% of patients, but one-third of those died later during the same admission. Major complications included renal failure requiring renal replacement therapy (63%), bleeding requiring re-exploration (41%), neurologic events (12%), and limb ischemia (15%). On multivariable analysis, older age, prolonged ECMO duration (>7 days), lactate >10 mmol/L at cannulation, and need for high-dose vasopressors were independently associated with mortality. Conclusion: ECMO remains a vital rescue option in cardiac surgery but is associated with substantial mortality and morbidity. Careful patient selection, early initiation before profound tissue hypoperfusion, and structured management protocols may improve outcomes. The data support the development of institutional ECMO bundles and adherence to international consensus recommendations for postcardiotomy ECMO.