Effective information technology service provision is key to the success of organisations. This paper presents results from five Australian organisations that implemented the Information Technology Infrastructure Library (ITIL). As a consequence, all these organisations have transformed their IT service management to provide significant benefits to their organisations, such as more rigorous control of testing and system changes, more predictable infrastructure, improved consultation with IT groups within the organisation, reduced server faults, seamless end-to-end service, documented and consistent IT service management processes across the organisation, and consistent logging of incidents. Key success factors for ITIL implementation include effective engagement of the personnel affected, support from senior management and communication of results.