Retrospective analysis from June '89 to January '91 of 198 patients seen in our Hospital for ureteral lithiasis using 'in situ' ESWL as the first therapeutic choice. The number of sessions per calculus was 1.45, 68.7% cases receiving only one session. 84.2% calculi were resolved by ESWL, with associated instrumental manoeuvres in less than 15% cases. Our hospital's therapeutic algorithm for the 15.8% calculi where ESWL failed is presented. The conclusion is that 'in situ' shock wave extracorporeal lithotripsy represents a perfectly valid alternative for the treatment of ureteral lithiasis regardless its location.