To investigate the effectiveness of an educational Quality Use of Medicines program, delivered at the level of general practice, on medicines use, falls and quality of life in people aged > or = 65 years. Cluster randomised controlled trial conducted in 2002. General practices in the Hunter Region, New South Wales, Australia. Twenty general practitioners recruited 849 patients to participate in the study. Education (academic detailing, provision of prescribing information and feedback); medication risk assessment; facilitation of medication review; financial incentives. a composite score reflecting use of benzodiazepines, non-steroidal anti-inflammatory drugs (NSAIDs) and thiazide diuretics; secondary measures: use of medication reviews, occurrence of falls, quality of life (as assessed by SF-12 and EQ-5D survey scores. Compared with the control group, participants in the intervention group had increased odds of having an improved medication use composite score (odds ratio [OR], 1.86; 95% CI, 1.21-2.85) at 4-month follow-up but not at 12 months. At 4-month follow-up, the intervention group had reduced odds of using NSAIDs (OR, 0.62; 95% CI, 0.39-0.99) and showed a non-significant reduction in use of benzodiazepines (OR, 0.51; 95% CI, 0.20-1.30) and thiazide diuretics (OR, 0.70; 95% CI, 0.48-1.01). Changes in drug use were not significant at 12-month follow-up. At 12 months, intervention-group participants had lower adjusted ORs (AORs) for having a fall (AOR, 0.61; 95% CI, 0.41-0.91), injury (AOR, 0.56; 95% CI, 0.32-0.96), and injury requiring medical attention (AOR, 0.46; 95% CI, 0.30-0.70). Quality-of-life scores were unaffected by the intervention. Education and systems for medication review conducted by GPs can be used to improve use of medicines. These interventions are associated with a reduction in falls among older people, without adverse effects on quality of life.