Objectives: to evaluate the wall-incorporated valve technique in prevention of reflux in orthotopic bladder substitutes. The evaluation includes the surgical technique and its applicability as well as the post-operative outcome.Materials And Methods: 37 patients were included in this prospective study of which 30 patients only completed the follow up period. All candidates for orthotopic urinary diversion were included with no specific selection criteria. The technique was applied in the first 18 patients. Unsatisfactory results were encountered, and this urged us to make a modification of this technique in the next 12 patients, we named the modified technique as the flat-segment technique. Follow up was done for all patients up to 6 months post-operatively. Results: Reflux prevention was successful in only 33% of patients in whom the wall-incorporated valve technique was used, with 61% reflux, and 6% stenosis of the valve segment, a complication that is unique to this technique. When using the flat-segment technique, the success rate in reflux prevention was 92% with 8% reflux (1 patient) and no cases of obstruction. The upper tracts were preserved or improved in the 12 patients. The rate of asymptomatic bacteriuria was 70% of all the 30 patients. Incidence of recurrent attacks of pyelonephritis with deterioration of renal function was 10%, and it occurred only in refluxing patients. The rate of requiring CIC was 40% of all patients.Conclusions: A new technique for reflux prevention in orthotopic ileal bladder substitutes was developed. The technique is simple, easy to learn, carries no additional morbidity to a standard refluxing technique but having the advantage of effective reflux prevention. Reflux prevention appears to be of importance in orthotopic bladder substitution if a high rate of bacteriuria is expected.