Background <p>Chronic subdural hematoma (CSDH) is a prevalent neurosurgical condition with a high recurrence rate after burr-hole surgery. The optimal duration of postoperative drainage remains controversial, with varying clinical practices worldwide.</p> Objective <p>This systematic review and network meta-analysis aimed to determine the optimal postoperative drainage duration to minimize recurrence while maintaining favorable clinical outcomes.</p> Methods <p>A comprehensive search was conducted across five databases up to January 2025, including randomized controlled trials (RCTs) and cohort studies evaluating the postoperative drainage duration in CSDH patients undergoing burr-hole surgery. The primary outcome was recurrence rate, while the secondary outcomes included mortality and functional outcomes. A random-effects network meta-analysis was performed, and the risk of bias was assessed using standardized tools.</p> Results <p>Seven studies with 1,842 patients were included, comprising three RCTs and four cohort studies. Drainage durations of 3 and 6 days significantly reduced recurrence rates compared with shorter durations (0–8&#xa0;h and 17–24&#xa0;h). Notably, the 6-day drainage had the highest probability (86.2%) of minimizing recurrence, followed by the 3-day drainage (13.8%). A shorter drainage duration (&lt; 24&#xa0;h) was associated with higher recurrence risks. However, no significant differences in mortality rates were observed across the drainage durations.</p> Conclusion <p>This study highlights that longer postoperative drainage durations (3–6 days) may reduce recurrence rates after burr-hole surgery for chronic subdural hematomas. However, its effect on mortality remains unclear. These findings support the importance of optimizing the drainage duration and call for further high-quality studies to guide clinical practice.</p>