Thirty children, 20 males and 10 females, aged 6.57 +/- 0.78 on the average (range: from 13 to 6 months), weighing 21.60 +/- 2.25 kg with bacterial infections of the upper respiratory tract and ear were admitted to the present trial. A chemotherapeutic agent based on amoxycillin and clavulanic acid in the suspension for children of 312.5 mg/5 ml (4:1 ratio) at the dosage of about 17 mg/kg in two daily administrations according to the weight of the patients was used. The therapy was prolonged for 8.87 +/- 0.30 days on the average, from a minimum of 3 to a maximum of 11 days. In the course of the treatment the symptom parameters and the objective signs progressively reduced until disappearance; the body temperature came promptly back to normal values, confirming the definite improvement and the regression of the infectious pictures. The microbiological data also fully confirmed the successful activity of the chemoantibiotic drug used. No side effects were found and, as regards local and general tolerance, no signs of an even slight impairment related to the administration of the drug were found. The final judgement expressed on the efficacy, on the basis of the more or less quick and complete symptom regression, evolution of the infectious picture and good tolerance were the following: excellent in 22 cases, good in 6, fair in 1 and not able to be evaluated in 1 case (a female patient who left off the trial).