The knee joint is surrounded by multiple bursae, which are fluid-filled sacs whose main function is to reduce friction during movement. Extrusion of fluid from the bursa sac due to trauma or overuse can lead to the formation of cysts in the adjacent region. Operative treatment for cysts involves excision, traditionally performed as open surgery, which is associated with complications such as poor wound healing or recurrence. This Technical Note describes the arthroscopic excision of a deep infrapatellar cyst as an alternative to open surgery.