Abstract:[Objective] To evaluate the clinical efficacy and safety of arthroscopic valvulotomy in figure-4 position for popliteal cysts. [Methods] A retrospective study was done on 34 patients who received arthroscopic valvulotomy in figure-4 position for popliteal cysts in our hospitals from January 2017 to July 2021. The clinical and imaging data were evaluated. [Results] All patients were operated on smooth- ly without serious complications, whereas with the operation time of (41.4±8.4) min, intraoperative blood loss of (20.4±3.3) ml, postoperative drainage volume of (104.5±29.5) ml, postoperative walking time of (3.7±0.9) days, and hospital stay of (7.5±1.4) days. All patients were fol- lowed up for an average of (16.3±3.8) months. With time elapsed preoperatively, 6 months postoperatively and the latest 6 months follow-up, the VAS score [(6.4±2.5), (3.8±2.4), (0.4±0.1), P＜0.05] significantly reduced, whereas the HSS score [(43.7±11.4), (73.8±12.6), (96.8±3.5), P＜0.05] and knee extension-flexion range of motion (ROM) [(82.8±3.3)°, (93.4±4.0)°, (105.9±1.3)°, P＜0.05] significantly increased. At 6 months after surgery, 1 patient recurred with a cyst size of 3cm×1cm, without treatment again. At the latest follow-up, 2 cases recurred and were excised by open surgery. [Conclusion] The clinical results of arthroscopic valvulotomy in figure-4 position are satisfactory for poplite- al cyst.