In many countries, prescription data are used as an instrument to provide feedback on prescribing. This article describes the development and implementation of a computer program as a tool for pharmacotherapy audit meetings and it illustrates the possibilities of such a program. The program was developed to support the optimisation of prescribing in the various stages of behavioural change. It enables pharmacists to make sophisticated overviews of prescribing by physicians in their audit group and furthermore, pharmacists can conduct drug utilisation studies or pharmaco-epidemiological studies in their own patient population. Forty percent of Dutch pharmacies have purchased the computer program since its introduction; it was distributed together with a technical handbook and a course book, which elaborated on the types of graphs available and their interpretation. An educational course was developed regarding the optimal selection and interpretation of graphs. Examples of prescription data as a tool to support various aims of audit meetings are given. The program is acknowledged as a welcome contribution to pharmacotherapy audit and to the pharmacists' advisory role in pharmacotherapy.