We studied the frequency of patients who had chronic subdural haematomas (CSDH) and Huntington's disease (HD) in a 1-year study period. In our department a total of 58 patients with CSDH were treated. Four patients (6.9% of them) had HD. Surgical evacuation of the haematoma was performed in all four cases with the use of a twist drill trepanation without a drainage system.