Ultrasonography is very suitable for diagnosis of urinary diseases. Urinary blader is anechoic and could be used as a reper for examination of neighbouring organs. Acute and chronic cistitis could be diagnosed on the basis of thickness of the blader walls, alteration of their structure and hypoechoic content, rich in inflammatory cells. Urolyts could be easily seen on the basis of the hyperechogenity and the posterior shadow, but those from the blader could be confused with the gas from colon. Nephritis could be diagnosed on the basis of the alteration of the echogenity and the report between cortical and medular region. For an accurate diagnosis ultrasound exam must be correlated with a carefully clinical exam, blood and urine biochemistry, haematological exam and specific tests for identification of the ethiological agent (bacteriology, virusology, serology etc).