We wanted to determine the absorption and clinical effect of sublingual (SL) and transdermal apomorphine in parkinsonism. Patients received single SL apomorphine doses (N = 7) and the absorption was compared with parenteral (N = 5) and oral (N = 4) doses. One patient received a transdermal dose of apomorphine. The relative bioavailability of SL apomorphine ranged from 10 to 22% of a parenteral apomorphine dose. Oral apomorphine was less than 4% bioavailable, and the transdermal dose did not produce detectable plasma levels. Three patients with motor fluctuations responded to SL apomorphine, with a latency to effect of 20-40 min and a duration of effect of 15-100 min. One patient used SL apomorphine as an adjunct with levodopa, and during 1 month reported a large decrease in "off" periods. We conclude that apomorphine is effectively absorbed by the sublingual route.