Objectives-To assess the risks and benefits of antibiotic treatment in children with symptoms of upper respiratory tract infection (URTI). Design-Quantitative systematic review of randomised trials that compare antibiotic treatment with placebo. Data sources-Twelve trials retrieved from a systematic search (electronic databases, contact with authors, contact with drug manufacturers, reference lists); no restriction on language. Main outcome measures-The proportion of children in whom the clinical outcome was worse or unchanged; the proportion of children who suVered complications or progression of illness; the proportion of children who had side eVects. Results-1699 children were randomised in six trials that contributed to the meta-analysis. Six trials were not used in the meta-analysis because of diVerent outcomes or incomplete data. Clinical outcome was not improved by antibiotic treatment (relative risk 1.01, 95% confidence interval (CI) 0.90 to 1.13), neither was the proportion of children suVering from complications or progression of illness (relative risk 0.71, 95% CI 0.45 to 1.12). Complications from URTI in the five trials that reported this outcome was low (range 2-15%). Antibiotic treatment was not associated with an increase in side eVects compared with placebo (relative risk 0.8, 95% CI 0.54 to 1.21). Conclusions-In view of the lack of eYcacy and low complication rates, antibiotic treatment of children with URTI is not supported by current evidence from randomised trials. (Arch Dis Child 1998;79:225-230)