Results og an open, controlled three-month clinical trial of therapeutical efficacy of a combination of a low doses of levodopa/carbidopa and bromocriptine in 20 de novo patients with Parkinson's disease (PD) are presented. All patients received the same daily doses of levodopa/carbidopa (250 mg), while daily dosage of bromocriptine was gradually increased from 1.25 mg to 30 mg. Owing to development of adverse effects 3 patients dropped out of the study, while in 70% of the patients who completed the protocol improvement of motor functioning exceeded 50%. Those with bradykinesia and rigidity responded most favorably. For all our patients the mean daily dose of bromocriptine was 26.25 mg. The most common adverse effects of the therapy were orthostatic hypotension (7 pts) and nausea (5 pts). The results of the study coincide with the hypothesis that comparative administration of low doses of bromocriptine and levodopa is the best approach to treatment of early phases of PD.