OBJECTIVE One or two burr-hole craniostomies with subgaleal or subdural drainage system and irrigation are the most common methods for surgical treatment of CSDH. The aim of this study is to compare the advantages or disadvantages of these techniques used for CSDH. METHODS Seventy patients were treated by burr-hole subdural drainage or subgaleal drainage system with irrigation. Our patients were classified into two groups according to the operative procedure as follows: Group I, one or two burr-hole craniostomy with subgaleal closed system drainage and irrigation (n=36), Group II, one or two burr-hole craniostomies with subdural closed drainage system and irrigation (n=38). We compared male and female ratios, complication rates, and age distribution between groups. RESULTS There was no remarkable difference between recurrence rates of the two groups. Recurrence rate was 6.25% in Group I and 7.8% in Group II. Subdural empyema occurred in one of the patients in Group II. Symptomatic pneumocephalus did not develop in patients. Four patients were reoperated for recurrence at an average of 12-20 days after the operation with the same methods. CONCLUSIONS Both of the techniques have a higher cure rate and a lower risk of recurrence. However, subgaleal drainage system is relatively less invasive, safe, and technically easy. So it is applicable for aged and higher risk patients.