Patients with Parkinson's disease (n = 68) switched from pergolide or bromocriptine to ropinirole overnight (dose equivalence ratios 1:6 and 10:6, respectively). The activities of daily living score for the Unified Parkinson's Disease Rating Scale (UPDRS) was significantly improved 4 weeks after the bromocriptine-ropinirole switch. All other UPDRS scores, including that for the side-effect component, were not significantly different after either switch. Overnight switching may be a safe therapeutic approach that may reduce hospitalisation and related socio-economic costs.