AbstractAimThe aim of this study was to examine the effectiveness of supporting intensive care units on implementing the guidelines.BackgroundQuality of care can be achieved through evidence‐based practice. Guidelines can facilitate evidence‐based practice, such as the guidelines ‘End‐of‐life care in the intensive care unit, nursing care’. Before intensive care nurses are able to use these guidelines, they needs to be implemented in clinical practice. Implementation is a complex process and may need support.DesignCluster randomized controlled trial.MethodsIntensive care nurses of eight intensive care units in the intervention group followed a supportive programme that educated them on implementation, strategies, goals, project management and leadership. The intervention group focused on a stepwise approach to implement the guidelines. The control group (n = 5) implemented the guidelines independently or used the standard implementation plan supplementary to the guideline. The effectiveness of the programme was measured using questionnaires for nurses, interviews with nurses and a questionnaire for family of deceased patients, in the period from December 2014–December 2015.ResultsOverall, an increase in adherence to the guidelines was found in both groups. Overall, use of the guidelines in the intervention group was higher, but on some aspects the control group showed a higher score. Care for the patient and the overall nursing care scored significantly higher according to family in the intervention group.ConclusionThe increase in adherence to the guidelines and the significantly higher satisfaction of family in the intervention group indicate that the supportive programme had a more positive effect.