To compare the clinical presentation, etiological factors and the outcome of chronic subdural haematoma (CSDH) in young and old adults, a retrospective analysis was performed by differentiating young adults, age<40 years ( n=24) versus extremely aged adults, age>75 years ( n=51). The clinical data, computed tomography (CT) findings and surgical outcome were recorded for analysis. We observed certain characteristics particular to young CSDH patients, higher incidence of headache ( P<0.001) and vomiting ( P=0.009), the shorter duration from trauma to operation ( P=0.018) and more severe traumatic episodes ( P=0.001). The older patients had a higher frequency of mental change ( P=0.006), motor deficits ( P=0.014) and larger haematomas ( P<0.001). The surgical complication rate was not statistically different between the two age groups. An understanding of the varied clinical presentation of CSDH is essential to stimulate clinical suspicion and prompt evaluation, particularly for the differences between young and extremely aged patients.