Summary: A 19-year-old female basketball player had chronic compartment syndrome. During basketball playing, she complained of bilateral lower leg pain that disappeared after several minutes of rest. Theintracompartmental pressure in the anterior compartment was 41mm Hg on the right side and 29 mm Hg on the left side immediately after playing. Prolonged ischemia of the anterior compartment was observed in comparison with four normal controls using near-infrared spectroscopy. Magnetic resonance imaging also revealed that the anterior compartment was mainly affected. Endoscopic fasciotomy was performed using an arthroscope, a transparent outer tube, and a retrograde blade. After the operation, her symptoms disappeared. Three months postoperatively, the anterior compartment pressure decreased and prolonged tissue ischemia improved. Endoscopic fasciotomy allowed us to cut the fascia safely and less invasively. We concluded that this technique is useful in treating chronic compartment syndrome in the anterior compartment of the lower leg. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 4 (May-June), 1999: pp 439–443