Intracerebral-intraventricular haematoma was created experimentally by injecting coagulated autologous blood into the left cerebral hemispheres of rats, stereotactically 2200 U. Urokinase was injected into the haematomas of the treated group and the same volume of physiologic saline solution into the control group. Macroscopic evaluations were made at the end of 24 and 48 hours and lysis of the haematoma was observed in 90% of cases in the group treated with Urokinase. This ratio was 20% in the control group (P < 0.00001). In microscopical evaluation, no histopathological changes were observed in surrounding tissues in either group. It is concluded that local Urokinase administration may be an effective method of treatment in intracerebral aematomas.