Spinal arachnoid cysts are oftenly caused by trauma, infection or inflammation. Most of these cysts are been detected incidentally while rutine controls. They are generally benign and do not cause any complaints. Here we present a 34-year-old patient who had undergone spinal instrumentation for 4 years ago due to vehicle accident. He had no complaints up to 6 months. Progressive incontinence, premature ejaculation and nubness/weakness on right leg were developed recently. Radiological examinations showed intardural spinal arachnoid cyst compressing spinal cord. After successful surgical resection, the patient's complaints regressed. Although conservative treatment is prefered for asymptomatic spinal arachnoid cysts, surgical decompression should be performed for sypmtomatic cases.