Upper gastrointestinal endoscopy plays a major role in diagnosis and management of upper gastrointestinal disorders. Lack of patient's knowledge regarding endoscopy procedure is the main reason for increasing anxiety. This study aimed to: Assess knowledge and anxiety levels of patients undergoing upper gastrointestinal endoscopy. The study was carried out: In the gastrointestinal endoscopy units, Tanta University Hospital: A convenience sample of adult patients with GI disorders admitted to GI endoscopy units at Tanta University Hospital and scheduled for GI endoscopy were recruit to the study. The research questions include, - What are the levels of knowledge of patients undergoing upper GI endoscopy at Tanta University Hospital? - What are relations between levels of state and trait anxiety and different variables? Tools of the study: Two tools were used, Tool (I) Structured interview questionnaire: This tool was developed and used by the researcher for collection of baseline data and is consisted of three parts: Socio demographic data, patient's clinical information and patient's knowledge regarding upper gastrointestinal endoscopy. Tool (II) The State Trait Anxiety Inventory Scale: The original scale was developed by Spielberger in to evaluate respectively, state and trait anxiety. Results: It was observed that Less than half ( . ) of studied patients had poor knowledge score, while ( ) had severe state anxiety and more than half ( ) had severe trait anxiety. there was a high negative significant correlation (r= - , - respectively) between knowledge and The State Trait Anxiety Inventory Scale. Conclusion: Providing information to the patient before upper gastrointestinal endoscopy, decrease their level of anxiety and improve tolerance level during endoscopy procedure. Recommendations: It was recommended that provision of institutional written policies and guidelines regarding increasing knowledge and declining anxiety for patients undergoing upper gastrointestinal endoscopy.