Background: Bariatric surgery has gained prominence over the past few decades as an effective intervention for managing morbid obesity and its associated comorbidities and serves as a powerful tool for weight control and health improvement. However, its success is not solely determined by the procedure itself but rather by the patient’s commitment to adopting a new lifestyle pattern. Aim of study: Was to assess lifestyle pattern modification for patients post bariatric surgery. Research design: A descriptive research design was utilized to conduct this study. Setting: This study was conducted at Surgical Outpatient Clinic affliated to Benha University Hospital. Sample: Purposive sample of 79 patients was used to conduct this study in the previously mentioned setting. Tools: Three tools were used to collect data in this study. Tool I: A structured interviewing questionnaire that included; socio-demographic characteristics, past history, anthropometric measurements of the patients with bariatric surgery, and knowledge of the patients regarding obesity and bariatric surgery. Tool II: Lifestyle pattern of the patients with bariatric surgery. Tool III: Attitude of the patients regarding bariatric surgery. Results: 54.4% of the studied patients had poor total knowledge level regarding obesity and bariatric surgery. 69.6% of the studied patients had unhealthy total lifestyle pattern level regarding bariatric surgery. 74.7% of the studied patients had negative total attitude level regarding bariatric surgery. Conclusion: There were highly statistically positive correlation between the studied patients’ total knowledge, total lifestyle pattern, and total attitude (P