The mobile lithotriptor is a new method of providing extracorporeal shock wave lithotripsy (ESWL) directly to the smaller urological centres. The unit, containing a Dornier HM4 lithotriptor, has treated 135 patients with a total of 168 treatments in 2 centres in the Oxford region. The overall success rate was 87% with no serious morbidity or mortality. The results compare well with the results from larger centres and the system is cost-effective. We suggest that it is one of the best methods of providing ESWL to the smaller urological centres.