Urinary bladder having a function of storing urine, covered by mucosa and having muscle layer on its wall is a global organ. There are two main functions of the bladder. 1-Storing urine with low-pressure as possible until the maximum filling capacity, 2-during urination absolutely excreting the urine by maximum compressive force. The common factors excreting the bladder are compressive force of the bladder and flow resistance caused by the factors belonging prostate and urethra. Nowadays, bladder geometry as an additional factor is discarded because all bladders are assumed to have a standard spherical shape. In this study, it is observed that the geometry obtained by MRI sagittal section differs from patient to patient. The bladder has a pineal shape and differs to a spherical shape as the patient age increases. Therefore, the study planned that the shape can be a factor affecting the urine flow. Since clinical data include urethral and prostate dependent factors, computer simulation of the urinary bladder is done and the effect of the bladder geometry on urine flow is estimated. It is observed that the bladder having pineal shape provides more pressure and flow rate than the bladder having spherical shape in clinical data. Therefore, bladders having pineal and spherical shape are simulated using Fluent software which performs finite element method and the flow rates and pressures are measured. As a result, It is observed that bladder having pineal shape has a more flow rate and pressure.