Fifty-eight paediatric patients aged one month to 14 years, who met the inclusion criteria for urinary infection, were studied. They were administered amox/clav at a dose of 21.9 +/- 2.96 (mean +/- SD) mg/kg/day for ten days. E. coli was isolated in 53 cases, P. mirabilis in two, K. pneumoniae in two and E. cloacae in one. Of the E. coli, 94.34% were sensitive to amox/clav, 67.92% were resistant to ampicillin, three cases showed intermediate sensitivity and the case of E. cloacae was resistant. These four patients were withdrawn from the study, and four more who did not come for follow-up. Of the 50 assessable patients, 94% were cured. Three days after completing the treatment, three patients (6%) still had a positive uroculture, although only one showed symptoms. Of the remaining 47, five cases (11%) presented bacteriological relapse in the culture made seven days later. Only 10% of the patients showed any type of gastrointestinal disturbances, and interruption of treatment was not necessary. The amox/clav combination, in view of its broad spectrum, easy administration by oral route and good tolerance, should be taken into account as a first choice treatment in urinary infections in paediatric patients of any age.