Background: Gastroesophageal reflux disease (GERD) is the most common upper gastrointestinal disorder among the elderly. Aim of the study: This study aimed to evaluate the effect of a lifestyle modification program on the geriatric patients with GERD. Subjects and methods: Design: A quasi-experimental, one-group pre-post intervention research design was used. Setting: The study conducted at El-Raghey Hospital for Gastrointestinal and Liver Diseases, Assiut University Hospitals, Egypt. Subject: The study included 70 elderly patients with a mean age of 66.51±7.61 years. Tools of data collection: Four tools were utilized to assess patients' personal data, health condition, GERD knowledge, symptom frequency, health-related quality of life, and lifestyle modifications. Results: Results showed a significant improvement in knowledge, GERD symptoms, and quality of life after the intervention, with a statistically significant difference (P < 0.001). Conclusion: These findings highlight the positive impact of lifestyle modification programs on geriatric patients' health. Recommendation: Therefore, increasing awareness of GERD among high-risk elderly populations is strongly recommended.