The factors associated with hematoma enlargement were analyzed in 24 patients, 16 males and eight females aged 46 to 77 years (mean 58 years), undergoing chronic hemodialysis who were admitted to our hospital with intracerebral hemorrhage between 1994 and 2003. Computed tomography demonstrated hematoma enlargement in eight patients after admission. Age, sex, duration of dialysis, time interval between onset and admission, site of hemorrhage, and blood pressure on admission were not significantly different between patients with and without hematoma enlargement. However, level of consciousness, size and shape of hematoma, prothrombin time, and fibrin degradation product level were significantly different between the two patient groups (p < 0.05). All patients with hematoma enlargement died during the course of treatment. Intracerebral hemorrhage is more difficult to treat in hemodialysis patients than in non-hemodialysis patients, and the outcome is especially poor in patients with large hematoma. The present study suggests that lower level of consciousness, large and irregular hematoma, prolonged prothrombin time, and high fibrin degradation product level are predictors of hematoma enlargement after admission.