Apomorphine a dopamine receptor agonist was given subcutaneously to 57 levodopa treated parkinsonian patients with refractory off-period disabilities for a median period of 16 months. In 30 given intermittent suprathreshold injections the mean number of hours spent in a disabling off state fell from 6.9 to 2.9. Similar benefit was observed in 21 patients receiving continuous infusions with additional boluses on demand by mini-pump (mean reduction of hours off from 9.9 to 4.5). Twelve patients have been treated for over two years without tachyphylaxis or loss of response. The incidence of neuropsychiatric side-effects has been low (7%). Six patients failed to show a sustained worthwhile response; severe disabilities during "on" periods being the major problem. Subcutaneous apomorphine is proposed as an effective treatment for patients with incapacitating "off" period disabilities refractory to oral medication and should be considered before experimental implantation procedures.