Abstract:This study aimed to determine the effect of early preparation on anxiety level among patients undergoing upper gastrointestinal endoscopy. A quasi-experimental research design was utilized to achieve the aim of the study. The study was conducted in endoscopy unit of Menoufia University hospital, Egypt. A purposive sample of 300 adult patients who undergoing upper gastrointestinal endoscopy was undertaken. The data gathering instruments were Bio sociodemographic and knowledge assessment form, Beck anxiety inventory scale. There was statistically significant improvement in knowledge related to preparation for upper gastrointestinal endoscopy and reduction in anxiety level in study group more than their control (P<0.001). The study concluded that, knowledge preparation for upper gastrointestinal endoscopy has shown a beneficial improvement of knowledge related to the procedure and reduction of anxiety level among patients. The study recommended that knowledge preparation for upper gastrointestinal endoscopy should form an important concern for patients before performing the procedure that lead to reducing anxiety level.