<b>Purpose</b><br/>This study aims to investigate the clinical outcomes and safety of a standardized two-session catheter-directed ethanol sclerotherapy protocol for peritoneal inclusion cysts. <br/><b>Materials and Methods</b><br/>Between November 2020 and July 2025, six women (median age, 32.5 years) with symptomatic peritoneal inclusion cysts underwent ethanol sclerotherapy. After complete drainage using an 8.5-Fr or 10.2-Fr pigtail catheter, two sessions of sclerotherapy were performed on consecutive days. In each session, 99.5% ethanol (50% of the aspirated volume, up to 150 mL) was instilled and retained for 20 minutes. Follow-up ultrasound was performed at 1, 3, and 6 months. Technical success was defined as successful completion of both sessions with a 20-minute ethanol retention time, and clinical success was defined as symptom improvement with a >50% decrease in cyst diameter at 3 months. <br/><b>Results</b><br/>Technical success was achieved in all cases (6/6, 100%). The median maximum cyst diameter significantly decreased from 14.0 cm (range, 6.0 to 20.0 cm) to 5.25 cm (range, 2.0 to 8.0 cm) at the follow-up within 1 month (p = 0.03). Clinical success was achieved in all cases at 3 months (6/6, 100%). No residual cysts were visualized on follow-up ultrasound at 6 months in all patients (6/6, 100%). Anti-Müllerian hormone levels measured in four patients showed heterogeneous changes, precluding definitive conclusions regarding the impact on ovarian reserve. No major complications occurred. <br/><b>Conclusion</b><br/>Two-session catheter-directed ethanol sclerotherapy appears to be a safe and effective minimally invasive alternative to surgery for peritoneal inclusion cysts, providing a high rate of complete resolution.