OBJECTIVES: To assess the effectiveness and safety of delayed antibiotic prescription (DAP) compared to immediate antibiotic prescription (IAP) and no antibiotic prescription (NAP) in children with uncomplicated respiratory infections. METHODS: Randomized clinical trial comparing 3 antibiotic prescription strategies. The participants were children with acute uncomplicated respiratory infections attended to in 39 primary care centers. Children were randomly assigned into prescription arms as follows: (1) DAP, (2) IAP, or (3) NAP. Primary outcomes were symptom duration and severity. Secondary outcomes were antibiotic use, parental satisfaction, parental beliefs, additional primary care visits, and complications at 30 days. RESULTS: In total, 436 children were included in the analysis. The mean (SD) duration of severe symptoms was 10.1 (6.3) for IAP, 10.9 (8.5) for NAP, and 12.4 (8.4) for DAP (P = .539), although the differences were not statistically significant. The median (interquartile range) of the greatest severity for any symptom was similar for the 3 arms (median [interquartile range] score of 3 [2–4]; P = .619). Antibiotic use was significantly higher for IAP (n = 142 [96%]) compared to DAP (n = 37 [25.3%]) and NAP (n = 17 [12.0%]) (P < .001). Complications, additional visits to primary care, and satisfaction were similar for all strategies. Gastrointestinal adverse effects were higher for IAP. CONCLUSIONS: There was no statistically significant difference in symptom duration or severity in children with uncomplicated respiratory infections who received DAP compared to NAP or IAP strategies; however, DAP reduced antibiotic use and gastrointestinal adverse effects.