Discal cysts are rare intraspinal extradural cysts that communicate with the corresponding intervertebral discs, and the diagnosis is difficult to distinguish from other causes of low back pain and radiculopathy. Optimal management for this type of cyst has not been determined because of its rarity. Here, we report successful treatment of a discal cyst and lumbar disc herniation using full endoscopic surgery in a professional baseball player with a chief complaint of weakness in his left lower leg. He had been treated conservatively but symptoms did not improve. Discography helped us to differentially diagnose discal cyst from other cystic lesions. Conventional surgical treatment would have resulted in considerable loss of baseball playing time for the patient. We opted to perform minimally invasive transforaminal full endoscopic surgery under local anesthesia to treat the discal cyst and lumbar disc herniation simultaneously without resection of bone and ligament handling. We removed the discal cyst and disc herniation, which released tension on the left nerve root at the L5 level, and then performed thermal annuloplasty to avoid recurrence. Postoperative course was good and he returned to play baseball at his original competitive level 3 months later. To our knowledge, there have been no previous reports of successful full endoscopic surgery for discal cyst and lumbar disc herniation performed simultaneously in a professional baseball player. It can be difficult to decide on the proper treatment for discal cysts, but full endoscopic surgery for symptomatic discal cyst might be one good option especially for elite athletes.