Ten advanced Parkinson pts (mean 8 years since diagnosis), 6 male and 4 female, 57 to 69 years old, mean 5.9 years on L-Dopa therapy, were put on Madopar HBS to assess the efficacy of the drug. All the pts had levodopa end-of-dose wearing-off type secondary motor fluctuations, 9 of them with dyskinesia and dystonia. Clinical evaluation was performed in basal conditions (pts on standard L-Dopa therapy) 1.6 and 12 months on Madopar HBS therapy. Parkinson signology was quantified with the modified Columbia scale (0 to 44), and motor fluctuations and dyskinesia with a scale 0 to 4 according to intensity and frequency. Pts received mean 1.150 mg. HBS daily dose plus 100 to 200 mg standard L-Dopa added to the early morning dose for a faster effect. At 12 months, a 60% decrease in "off" periods, a 50% decrease in feet dystonia, with no change in orofacial dystonia were observed. Dyskinesia decreased in intensity but not in frequency. There was a 50% decrease of Parkinson signology in "on" periods. In conclusion, Madopar HBS reduces the signology of the long-term Levodopa therapy syndrome and therefore is commendable in pts with advanced Parkinsonism.