In 1995, a meeting was arranged by the Radiation Oncology Committee of the British Institute of Radiology and the Royal College of Radiologists to look at the evidence of the impact of unscheduled gaps in radiotherapy on local tumour control, and to try to address some of the concerns that this raised. Following the meeting, guidelines were drawn up by a sub-committee of the Royal College of Radiologists to advise departments how to manage unscheduled interruptions or prolongation of radical courses of radiotherapy. One of their recommendations was that there should be regular audit of the outcome of the measures taken to avoid gaps in treatment. This paper presents how the guidelines were addressed in a department with one linac, together with the results of a 5-year audit.