Dopaminergic treatment with levodopa (L-dopa) has been proven as the treatment of first choice in patients with restless leg syndrome (RLS). Augmentation of symptoms and end-of-dose rebound phenomena under L-dopa/decarboxylase inhibitor treatment present major problems in some patients. To evaluate the efficacy of pergolide in RLS, we treated 15 patients suffering from severe RLS, who had previously experienced an augmentation of symptoms under long-term treatment with L-dopa, in an open clinical trial with pergolide. All patients reported an improvement of their RLS symptoms. Our study shows that pergolide, if administered at a mean dose of 0.4 mg in combination with domperidone, is a very effective drug in the treatment of sleep disturbances and daytime symptoms associated with RLS, and does not cause any serious side effects during the observation period of 6 months.