Intensive insulin therapy (IIT) for the management of high blood glucose can reduce mortality and morbidity in the critically ill. However, there is little published literature on how to implement it successfully. The aim of this study is to chronicle the development and difficulties encountered in implementing an IIT protocol in a critical care unit in a district general hospital. A nurse-led protocol was developed. Qualitative audit was undertaken during development and implementation to identify potential problems with using the Bath Insulin Protocol. Regular feedback sessions were introduced to encourage change and further identify problem issues. Qualitative audit led to changes in practice for individual nurses and changes to other unit protocols. The main change for individual nurses was to measure blood glucose hourly using a bedside glucometer. The unit's feeding and drug dilution policies were identified as a potential cause of glucose instability and were modified. To implement IIT successfully, it is necessary to consider changing working practices and to identify other unit protocols which can cause glucose instability. The additional nursing workload must be considered and appropriate means of supporting staff identified.