The attempt to restore lost neurological function through grafting of cate- cholaminergic tissue into the striatum is a dramatic new experimental treatment approach for parkinsonism. We have grafted autologous adrenal medullary tissue into the right caudate nucleus in 12 patients with advanced Parkinson’s disease (10 males, 2 females, mean age 53 years, mean Hoehn and Yahr stage ‘off medications 4.2) applying a transcortical technique similar to that of Madrazo as modified by Allen using right adrenalectomy performed via a flank approach. There have been no deaths, surgical complications, or serious postoperative morbidity. Modified Columbia Parkinson’s disease ratings of patients off all dopaminergic agents for 72 h revealed 22% improvement (p <0.01) 3-6 months postoperatively (n = 10) and 22% improvement (p <0.01) 7-12 months later (n = 9). Postoperative dyskinesias necessitated reduction of E-dopa by 11% and of carbidopa by 29%. Analysis of lumbar cerebrospinal fluid biogenic amine metabolites following a 4-day ‘drug holiday’ revealed that homovanillic acid increased to 159% of preoperative levels (p <0.01) 3-6 months (n = 9) and to 197% of preoperative levels (p <0.02) 7-12 months postoperatively (n = 5). We have observed a mild to moderate improvement persisting up to I year with this therapeutic approach, but further study is needed. © 1990 S. Karger AG, Basel.