This work reports the use of laparoscopic-transducer sonography for the examination of the urinary system in a swine model. Animals underwent a two-phase study. In the first phase, the urinary system was examined using laparoscopic sonography. In the second a partial ureteral obstruction was induced, and sonographic changes were recorded and evaluated. Sonography was used to evaluate kidneys, ureters, and bladder. Anatomic structures were evaluated and the following pathological findings were identified: renal cysts, one polycystic kidney, dilation of the renal pelvis, hydronephrosis, and one perirenal pseudocyst. Where necessary, contrast digital fluoroscopy (excretory urography and retrograde ureteropyelography) was also performed. Laparoscopic sonography mainly is used for evaluation prior to laparoscopic surgery to guide decisions relating to surgery. The quality of the images obtained laparoscopically is superior to that of percutaneous or transabdominal images, because artifacts are reduced and the contact surface of the transducer is placed directly over the study area. Laparoscopic sonography proved highly effective for studying renal and ureteral disorders prior to minimally invasive surgery.