The urinary system is the organ system responsible for the production, storage and elimination of urine. This system comprises urethra, bladder, ureters and kidneys. It correspond to the major system which filters the blood and any imbalance of this organ can increases the rate of being infected with diseases. There are various Urinary System diseases having related symptoms, therefore, the main important objective -in order to prescribe the appropriate treatment - is the right diagnosis of the disease. In this paper the design of the proposed Expert System which was created to help Urination Problems in diagnosing some of the Urination diseases (Pyelonephritis, Kidney Stone, Bladder infection, Prostatitis, Urethritis, Gonorrhea, Interstitial cystitis, Stress incontinence, Trauma in kidney or bladder ) are presented, an overview about the Urination diseases are displayed, the cause of diseases are outlined and the treatment of disease whenever is possible is given. SL5 Object language was used for designing the proposed expert system.