We determined the incidence of infectious complications (asymptomatic bacteriuria, urinary tract infection and urosepsis) in patients without associated risk factors treated with extracorporeal shock wave lithotripsy.We performed an observational, prospective cohort study between October 2010 and June 2013. We included all patients without risk factors who were treated with extracorporeal shock wave lithotripsy for kidney or ureteral lithiasis. All patients underwent urine culture 5 days before the procedure. Another urine culture was performed 7 days after lithotripsy. No patient received antibiotics.Initially 366 patients with a mean ± SD age of 53 ± 13 years were enrolled in the study. A total of 64 patients (17.5%) underwent extracorporeal shock wave lithotripsy with a previously placed Double-J® stent. After lithotripsy urine culture was positive in 20 patients (5.8%), of whom 4 (1.2%) presented with symptomatic urinary infection and the remaining 4.6% showed no symptoms. Urosepsis did not develop in any case. In our study patient age was an independent risk factor for bacteriuria after lithotripsy.The incidence of infectious complications after extracorporeal shock wave lithotripsy in patients without risk factors is low. This leads us to conclude that without defined risk factors antibiotic prophylaxis is not justified. Also, elderly patients were more at risk for bacteriuria after extracorporeal shock wave lithotripsy and, thus, for a possible infectious complication.