Background: This study compared the early success, complication and patient satisfaction rates of modified extraperitoneal radical cystectomy (Mainz II urinary diversion) with standard intraperitoneal radical cystectomy (continent ileocecal urinary diversion) in a group of patients with muscle invasive urothelial carcinoma of the urinary bladder.Methods: From September 2009 until November 2013, this randomized study enrolled 60 patients with muscle invasive transitional cell carcinoma of the urinary bladder who underwent radical cystectomy and urinary diversion. The patients were randomly allocated to two groups via block randomization. Group A included 30 patients (28 men and 2 women) who underwent modified small incision extraperitoneal radical cystectomy with a Mainz II urinary diversion. Group B included 30 patients (27 men and 3 women) who had classic intraperitoneal radical cystectomy and ileocecal continent diversion. The data were extracted and analyzed. The patients were followed for one year after surgery.Results: Group A patients had a mean age of 61.47±8.63 years. Group B patients had a mean age of 60.77±6.82 years. There were no statistically significant differences in blood loss, electrolyte and acid-base abnormalities, and early post- operative complication rates between the two groups. However, surgical and hospitalization times were significantly shorter in group A (P<0.001). In addition, patients were mobilized earlier and had shorter nothing by moth time. Patient satisfaction rate was significantly more in group A.Conclusion: Small incision extraperitoneal radical cystectomy and Mainz II urinary diversion is a safe, less complicated, effective and more rapid technique with excellent short term outcome. It seems this technique is a reliable alternative for continent urinary diversion in selected bladder cancer patients, mainly in those with urethral involvement.