Background: Gastroesophageal reflux disease (GERD) is a widespread disorder that generally refers to the unrestricted passage of stomach contents into the esophagus, which irritates the lining of the esophagus, causing uncomfortable symptoms. The study aimed to assess the knowledge and severity of symptoms among gastroesophageal reflux disease patients. Research design: descriptive research design. Methods: A purposive sample composed of sixty patients who met the inclusion criteria. The study was carried out at the Assiut University outpatient clinic of the AL-Rajhi Liver Hospital, Egypt. A demographic data sheet, GERD Knowledge assessment sheet, and Gastro-esophageal Reflux Disease Questionnaire were used to collect relevant data. Results: The participants' total knowledge score was poor. Most of the studied patients (83.3%) had severe symptoms of GERD. A highly statistically significant relationship was shown between the patient's characteristics, including occupation and educational attainment, and their overall GERD knowledge scores. Conclusion and recommendation: The study concludes that poor knowledge among GERD patients is common, and patients experience severe symptoms regardless of their level of knowledge. This suggests that factors other than knowledge, such as psychological well being and adherence to treatment, play a significant role in the severity of GERD symptoms. Further studies could explore these additional factors to develop more comprehensive management strategies for GERD patients.