Written information sent to patients prior to diagnostic gastroscopy is an important part of the process of informing and preparing them for the procedure. Yet there is ample evidence in the literature that information leaflets do not measure up to the required standard. In this study, information leaflets from a random sample of seven hospitals in Northern Ireland that carried out gastroscopy as a day procedure were evaluated using a checklist of items recommended by the British Society of Gastroenterology (BSG) for inclusion in leaflets for patients undergoing diagnostic gastroscopy. The results showed that the number of written materials sent to patients prior to the procedure varied between units. There were inconsistencies in the information given by the same unit, and overall, there was a lack of vital information in most of the leaflets. Some of the information was confusing and ambiguous. The potential risk of the procedure was explained in only one of the leaflets. Patients’ right to choose to have a mild sedative was not made clear in most of the leaflets. More should be done to address these gaps and inconsistencies in the written information provided to patients prior to gastroscopy.