A new lipophilic morpholino anthracycline derivative, MX2, has an antitumor activity against a wide spectrum of experimental tumors. We examined the effect of MX2 against experimental brain tumors. At a low dose, MX2 exhibited strong growth inhibitory activity against human and rat glioma cells. The survival time of rats with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells was significantly prolonged by intravenous MX2. The growth of subcutaneously implanted glioma in rats was significantly retarded by intravenous MX2. These results suggest that MX2 warrants further experimental evaluation of its efficacy against malignant brain tumors including gliomas.