Parkinson''s disease, because of its progressive degenerative nature, is associated with increased disability and mortality compared with mortality in the general population. We examined mortality data from three clinical trials involving 1,330 patients with Parkinson''s disease treated with pergolide as an adjunct to levodopa or levodopa/carbidopa therapy. The ratio of observed deaths to expected deaths in the general population of the same age, gender, race distribution, and period of observation was 2.3 for the 3 studies combined. The ratio is lower than that in Parkinson''s disease patients treated prior to the introduction of levodopa, consistent with ratios with levodopa and levodopa combination therapy. The ratio is slightly higher than in Parkinson''s disease patients treated with levodopa and levodopa combination therapy, which may be attributable to differing patient characteristics in the populations studied.