Endoscopic treatment of intractable chronic anterior and lateral exertional compartment syndromes of the lower leg in athletes is reported anecdotically only in six patients. H(0) = There is no difference between preoperative and postoperative status after endoscopic release of chronic exertional compartment syndromes of the lower leg. Case series; level of evidence, 4. We developed a minimally invasive, endoscopically assisted technique for release of chronic exertional compartment syndromes of the lower leg. All patients were investigated by telephone interview 47 months (range 5 months-7 years) after surgery. This investigation comprises release of 19 deep posterior, 16 anterior, and 3 lateral compartments in 17 athletes. No complications were seen following endoscopic anterior and lateral compartment decompression, while two patients following deep posterior compartment release underwent open revision surgery due to hemorrhage. Initial endoscopic surgery in these two patients was performed under tourniquet. There were no postoperative complications due to vascular injuries in all further patients who were operated without tourniquet. Ten patients returned to previous sport activity. At follow-up, results were good or excellent in 10 out of 17 patients. Visual analogue pain scale ranged from 5 to 9 (mean 7.4) before surgery and from 1 to 8 (mean 2.4) at follow up (P = 0.0005). This study confirms feasibility of endoscopic release for chronic exertional compartment syndromes of the lower leg on a larger scale. At least for the deep posterior compartment its safety and effectiveness cannot be recommended without stint as results are inferior as compared to data obtained from literature for open surgery. To avoid vascular complications, especially during deep posterior compartment fasciotomy it is most important to perform the procedure without tourniquet.