Background: Bariatric surgery refers to weight reduction surgeries for obese persons mainly by restricting their food consuming through a variety of surgical procedures performed on gastrointestinal tract by reducing the size of the stomach. Aim was to evaluate the effect of an educational program on minimizing complications for patients post bariatric surgeries. Design: One group quasi-experimental design was utilized to fulfill the aim of the present study. Setting: Surgical departments and outpatient clinics at Benha University Hospital. Sample: A purposive sample of 45 bariatric patients. Tools: Two tools were used in this study; tool I: Patients' structured interview questionnaire. Tool II: Postoperative complications assessment and follow up sheet. Results: Only more than one fifth of the studied patients had good level of knowledge at preprogram implementation compared to about half, two thirds & majority of studied patients respectively during 1st month, after 3 & 6 months post program implementation. There was a significant statistical difference between 3 months and 6 months post program implementation in relation to all items of late complication among the studied patients. Conclusion: Implementing of an educational program had statistically significant improvement of knowledge and complications among bariatric patients. Recommendations: Further studies should be carried out using a wider geographic scope and a larger sample size to acquire progressive improvement in patients' knowledge and complications and to attain more generalizable results.