186 patients with partial and 55 patients with complete renal staghorn calculi were treated with primary extracorporeal shock wave lithotripsy (ESWL) at the Department of Urology, University of Würzburg Medical School. Partial staghorn calculi required an average of 1.4, complete staghorn calculi an average of 2.2 treatment sessions using the Dornier HM 3 lithotriptor. 55% of all patients and 46% of the patients with complete staghorn calculi were rendered stone-free within 1 year after ESWL. Pretreatment urinary tract infections present in 50.6% of all patients could be reduced to 22.5% 1 year after ESWL. The most frequent complications after ESWL were ureteral obstruction caused by 'steinstrasse' (41.4%), fever (38.4%), and renal colics (29.4%). Severe complications needing open operative procedures or blood transfusions did not occur. 50% of all patients underwent auxiliary procedures (e.g. insertion of indwelling ureteral stents: 25.3%, percutaneous nephrostomy: 20.3%, percutaneous nephrolithotripsy: 2.9%). Pretreatment insertion of an indwelling ureteral stent was found to reduce posttreatment complications as well as the need for percutaneous nephrostomy only in patients with partial staghorn calculi. The data presented in this study demonstrate that primary ESWL therapy can be safely and successfully performed in the majority of patients with renal staghorn calculi. In patients requiring complete removal of all stone fragments, a percutaneous lithotripsy can be performed following ESWL.