We treated 20 early Parkinson's disease subjects with the dopamine agonist lisuride in combination with the MAO-B inhibitor selegiline (L-deprenyl). We started with lisuride alone for one month, then we added selegiline versus placebo to lisuride in double-blind conditions for 3 months; finally all patients received lisuride and selegiline for another 3 months. Lisuride alone (1.43 ± 0.10 mg) significantly improved PD. When selegiline (10 mg/day) was added in the double-blind phase the mean lisuride dosage could be reduced by 22.8% without deterioration of the clinical effects, and the same occurred in the former placebo group when selegiline was added. The combination of both drugs was well tolerated. These data are of interest for the interpretation of the effects of selegiline.