Background: Peptic ulcer disease (PUD) is one of the common gastrointestinal disorders and health challenges that resulted in a significant burden on elderly people. Aim: To assess knowledge, practices, and quality of life of elderly patients with PUD. Design: A Cross-sectional descriptive study design. Setting: Gastroenterology outpatient clinic at ‎ Zagazig University Hospitals. Subjects: A purposive sample included 150 elderly patients with PUD. Four tools of data collection: I) An interview questionnaire consisted of two parts about demographic characteristics and medical history of the studied elderly. II) Knowledge about PUD scale. III) Practices regarding PUD scale. IV) The WHO Quality of Life (QOL) Instrument-Short Form. Results: The study revealed that 51% of the studied elderly had satisfactory knowledge about PUD and 85% of them ‎had satisfactory practices regarding PUD. Regarding the total QOL score, 83.3% of the ‎studied elderly had poor QOL. Also, the study revealed that there was a significant negative correlation between the total score of ‎elderly QOL and their total knowledge score about PUD (r = -0.168). Conclusion: The study concluded that half of the studied elderly had satisfactory knowledge about PUD and the majority of them ‎had satisfactory practices regarding PUD. Also, the majority of the elderly patients had poor QOL and there was a significant negative correlation between ‎ QOL of the elderly and their knowledge about PUD. Recommendation: Developing and implementing appropriate and effective health education programs for elderly patients with PUD to increase their knowledge about PUD and to improve their quality of life.