The Global Rating Scale for endoscopy is a web-based tool that can be used to assess and improve the quality of an endoscopy service. It was developed by asking endoscopy health professionals what they would want from the service for themselves or their relatives if they were undergoing an endoscopic procedure. To date, the Global Rating Scale has not been validated by patients themselves. We used focus groups in order to access the views and opinions of patients who had recently had experience of endoscopy services. Six focus groups were undertaken in five different Health Board areas across Scotland; in total 26 people participated. The results indicated that from the patients' perspective the 12 items of the GRS covered all areas of the endoscopy experience. There were no specific concerns identified that were not already covered within the Global Rating Scale. We conclude that the Global Rating Scale does address quality issues that matter to patients undergoing endoscopy, and validates the use of the GRS as a quality assessment tool for endoscopy services.