Autograft of adrenal medullary tissue into the striatum was performed stereotactically in 5 patients with severe Parkinson's disease. Two patients had suffered from side effects of L-dopa, and 3 were severely disabled without L-dopa preoperatively. After surgery, the dosage of L-dopa could be reduced in 1, and L-dopa could be withdrawn in 4 patients. The results of adrenal medullary tissue transplantation in Parkinson's disease are analyzed.