To reduce the damage to posteromedial knee capsule, we developed a direct extra-articular arthroscopic approach for excision of symptomatic popliteal cysts. This study aimed to demonstrate the surgical technique and present the 2-year follow-up results. Cystectomy is performed by extra-articular surgical approach through a high posteromedial portal. Twenty-one consecutive patients diagnosed of symptomatic popliteal cysts with failed initial conservative treatments were included. At a median follow-up of 29.4 months, all knees had improved clinical function assessed by Rauschning and Lindgren knee classification (p<0.001). The cysts were either disappeared (95.2%) or reduced in size (4.8%). Only one (4.8%) patient had recurrent cyst, which was solved after ultrasound-guided aspiration. This direct extra-articular arthroscopic technique could be a feasible alternative for treatment of symptomatic popliteal cysts.