Background/Objective <p>Cardiovascular disease (CVD) remains a leading cause of global mortality, often necessitating complex surgical interventions involving extracorporeal circulation. Postoperative adaptation, particularly quality of life (QoL), is influenced by psychological and cognitive factors. This study investigated the predictive roles of executive functions, positive mental health, and dispositional optimism on postoperative QoL in patients undergoing cardiovascular surgery.</p> Methods <p>A cross-sectional study was conducted at the Center for Cardiovascular and Transplantation Surgery in Brno, Czech Republic. A total of 145 patients (mean age = 67.3 years) completed validated preoperative assessments, including the Verbal Fluency Test, Trail Making Test, and Stroop Test (executive functions), the Life Orientation Test-Revised (dispositional optimism), and the Mental Health Continuum-Short Form (positive mental health). Postoperative QoL was evaluated six months post-surgery using the Duke Health Profile. Multiple linear regression analyses were performed to determine significant predictors of QoL.</p> Results <p>Among all variables, only positive mental health was a statistically significant predictor of postoperative QoL (β = 0.179, p = 0.002). Neither executive function domains—cognitive flexibility, verbal fluency, psychomotor speed, resistance to cognitive load—nor dispositional optimism demonstrated significant predictive value. The final regression model accounted for 4.5% of the variance in QoL outcomes.</p> Conclusions <p>Positive mental health emerged as the sole psychosocial factor significantly associated with improved postoperative quality of life in cardiovascular patients. These findings highlight the need for integrating positive psychological assessments and targeted interventions into perioperative care to support recovery and enhance long-term outcomes.</p>