Objective To investigate the clinical characteristics and treatment strategy for arachnoid cyst combined with chronic subdural hematoma.Methods Nine cases of arachnoid cyst combined with chronic subdural hematoma, who received treatment in our hospital from January 2009 to January 2014, were retrospectively analyzed. Among these patients, there were 6 males and 3 females, with a mean age of 23.9 years (range, 1.5-60 years). Headache was seen in 8 cases, of whom 6 had nausea and vomiting, 1 had limb weakness, and 1 had limb convulsion. History of head injury was found in 6 cases.Results Five of the 9 patients underwent burr-hole irrigation and drainage (BHID) and fully recovered. Another 2 cases received craniotomy and evacuation of subdural hematoma and arachnoid cyst and also fully recovered. The other 2 cases received conservative treatment; cranial CT one month later revealed reduced hematoma, indicating that patients recovered without operation. All patients were followed up for 10 months to 4 years after discharge, and none had recurrent subdural hematoma.Conclusions Arachnoid cyst combined with chronic subdural hematoma is commonly found among young adults with a history of head injury. Patients with obvious clinical symptoms should receive surgery, and surgical decision concerning application of BHID or craniotomy and evacuation of subdural hematoma and arachnoid cyst depends on clinical manifestations including hematoma quantity and existence of hematocele.