A number of strategies have been shown to improve the quality of drug prescriptions. The objective of this study was to implement and assess the effectiveness of 3 interventions on physicians' prescribing and cost containment: training physicians about quality prescribing; regulatory and administrative measures to improve rational drug prescribing; and a multi-faceted approach using 2 these strategies plus additional elements. Three public health centres, 1 for each intervention, were randomly selected; 61 physicians were trained in drug prescribing and completed a pre-and post-training questionnaire; and 100 post-intervention prescriptions from each centre were compared. All 3 interventions effectively improved the quality of drug prescriptions and the notation of drug-related information and trainees returned positive evaluations of the training course. Whether or not physicians' improvement in prescribing will be sustained is unclear and therefore subsequent follow-up evaluations are needed.