Evaluation and follow-up of patients submitted to extracorporeal shock wave lithotripsy (ESWL) by ultrasonography is a good adjunct to radiology. Plain x-ray and ultrasound imaging permit following the course of stone patients submitted to treatment by ESWL without recurring to IVP in most of the cases. One-thousand kidney units corresponding to 931 stone patients were submitted to ESWL. Patient evaluation by ultrasound was performed prior to and 24 hours after treatment. Ultrasonographic evaluation is important because it permits: 1. Detection of changes in size, number, and site of the hyperechogenic image. 2. Evaluation and follow-up of urinary tract dilatation. 3. Control of radiolucent calculi thereby avoiding repeated explorations using contrast medium. 4. Detection of possible perirenal hematoma post-ESWL. 5. Diagnosis of other renal or extrarenal disorders.