In a retrospective study, the data of 102 patients were evaluated for effectiveness of treatment of upper ureteral calculi by extracorporeal shock wave lithotripsy (SWL) alone (in situ) or after repositioning of (push and smash) (53 cases). Whereas no significant differences were seen concerning the duration of stone impaction and obstruction, significant differences were found concerning the number of treatments per patient (1.5 v 1.2) and the number of shock waves (1500 v 1240) necessary to destroy the stones. The calculi treated in situ necessitated a considerably higher number of auxiliary measures (ureteral catheterization, double-J stent insertion). The stone-free rates after 6 months were comparable in the two groups. Ureteral catheter mobilization of obstructive upper ureteral calculi prior to SWL provides for short and uneventful passage of fragments.