The number of patients with urinary stones has been increasing worldwide, and this is assumed to be due to ageing of the population [1,2]. ESWL, which causes few complications, is expected to play a role in the treatment of elderly patients with urinary stones. In our hospital, ESWL was introduced in 1988, but since then we have felt that the fragmentation conditions are not as favourable in elderly patients. However, because of the few reported cases any correlation between age and fragmentation effects remain unclear [3,4]. Thus, we investigated the correlation between the efficacy of ESWL and patient age. The results of ESWL were assessed in 954 patients (750 males and 204 females) during the period 1999–2003 using radiography and a three-level scale, i.e. ‘favourable’ for cases in which the stone was disintegrated completely and had disappeared, ‘intermediate’ when the stone was fragmented and became thinner, and ‘poor’ when there was no change. The relationship between age and these results was analysed statistically; there was a significant decrease in the effect of ESWL with increasing age of the patients (Fig. 1, P = 0.011). Obviously the ease with which a stone can be fragmented depends on its size, position and composition, but the finding that stones are fragmented less easily in elderly patients is also important and the patient should be made aware of this before treatment.