Introduction and aim. At present, being a routine imaging procedure, endoscopy constitutes a significant tool in a diagnostic work-up and treatment of gastroenterological diseases, both in adults and children. The study aimed to assess the level of parents’ knowledge on gastroduodenoscopy in children hospitalized due to gastrointestinal diseases. Material and methods. A hundred of parents of children qualified for gastroduodenoscopy of the alimentary tract in the Gastroenterological Laboratory, Children’s Memorial Health Institute, Warsaw. 88 women and 12 men, aged between 26 and 50 years (mean age: 40 years, SD = 5.7). Most parents had secondary education (n = 44) or higher (n = 41) and lived in towns under 50,000 citizens (n = 52). A voluntary and anonymous questionnaire study was conducted by means of an original questionnaire that included 33 close-ended simple choice questions, 7 multiple choice questions, 3 open-ended questions. The study was conducted between October 1st, 2014 and January 30th, 2015. Results. A vast majority of parents (n = 88) reported a high level of knowledge on gastroduodenoscopy and they gained knowledge from physicians (n = 85) or the Internet (n = 58). Most of the study participants received oral (n = 88) and written (n = 74) information on the manner of the examination procedure. The study participants said that the information on preparation for the examination provided by the medical personnel was sufficient. Among the study group, a vast majority (n = 99) knew which parts of the alimentary tract were examined during gastroduodenoscopy and how to prepare their child for endoscopy. Conclusions. 1. Parents had a great knowledge of gastroduodenoscopy performed in children, the aim of the examination, and the manner of preparation their children for the examination. However, they had insufficient knowledge of possible complications following the examination. Therefore, more emphasis should be put on informing parents about possible complications. 2. Since a physician and the Internet constituted main sources of parents’ knowledge of gastroduodenoscopy, parents should be provided information on reliable online sources. 3. When educating parents, particular attention should be put on extending the time for asking questions, providing information on complications following the examination and increasing the role of nurses in the process of informing parents about the examination.

Key words: level of knowledge, parents, children, endoscopy, diagnostic work-up.