Nicotine will be employed at daily doses lower than those available OTC as smoking-cessation patches, in parkinsonian patients experiencing disabling dyskinesias due to their levodopa treatment. The principal adverse effect from this dose level of nicotine is expected to be nausea on acute administration to nicotine-naive patients. Because tolerance to the effects of nicotine is achieved by repeated dose, the study is designed to gradually escalate from 6 to 24 mg per day, taken in 6 separate oral doses of 6 mg each. The study is designed to see if doses which can be tolerated by parkinsonian patients will also reduce the severity and frequency of the dyskinesias experienced following administration of levodopa, the gold standard medication for Parkinson's disease.