Implementing clinical audits is an internationally recognised way of getting evidence into practice. Drug Treatment Centre pharmacies, due to the nature of the specialised services that they provide, are situated at different sites, and variations in practices were expected and accepted. The aim of the project was to develop and implement an audit programme across eight pharmacies within an eight month period. The objectives were to design/develop and test the audit tool by collecting data across all pharmacies in collaboration with the staff. The HSE Change Model was used for implementing the project. The stages of initiation, planning, implementation and mainstreaming were followed. Both qualitative and quantitative tools were used to inform the change process. Resistance to change was managed by participation and involvement of the staff. The audit tool was successfully developed and tested by collecting data. A comparison of results of the first audit with the re-audit revealed positive progression towards standardisation. Using a structured approach to the change process proved to be the success factor for sustained change delivery.