Many athletes complain of exercise-induced pain in the lower leg that can be caused by inflammatory diseases, peripheral nervous system disease, fatigue fracture, shin splint, and chronic compartment syndrome (CCS). CCS is the most typical exercise-induced condition and it often requires surgical decompression of the several compartments. There are already many techniques reported in the literature. Recently, an endoscopic technique for CCS was reported with which excellent results were achieved. We have modified it and developed a new technique for treating CCS of the lower leg. We report a case of CCS of the lower leg treated with 1-portal endoscopic fasciotomy. The technique helps to decrease damage to soft tissue and patients will immediately return to normal activities of daily living.