Introduction: Postoperative fatigue and cognitive dysfunction are common and debilitating complications, especially among older adults. These issues impair physical recovery, diminish autonomy, and reduce overall quality of life. While occupational therapy (OT) has shown potential in mitigating these symptoms, its specific contributions—particularly those involving chronobiological alignment—remain underexplored.

Materials and Methods: This mixed-methods study evaluated the effects of a specialized OT program on 60 postoperative patients aged 65 and older. Interventions emphasized cognitive engagement activities, energy conservation strategies, and alignment with individual circadian rhythms. Quantitative assessments included the Montreal Cognitive Assessment (MoCA) and the Fatigue Severity Scale (FSS), administered preoperatively and at two and six weeks post-intervention. Additionally, semi-structured interviews were conducted to capture patient perspectives on the therapy’s subjective impact.

Results and Discussion: Participants who received the tailored OT intervention demonstrated statistically significant improvements in MoCA scores (p < 0.01) and reductions in FSS scores (p < 0.05). Notably, patients whose therapy schedules were adjusted based on chronotype exhibited the greatest cognitive gains and fatigue reduction. Thematic analysis of qualitative data revealed improvements in sleep quality, motivation, and perceived cognitive clarity, suggesting that circadian-informed OT promotes not only functional recovery but also emotional and behavioral resilience. These findings highlight the value of integrating neurorehabilitation techniques with chronobiological principles to optimize patient outcomes in postoperative settings.