The objectives are to assess the efficacy of antibiotics in reducing post-tonsillectomy morbidities in children. This is a clinical trial study that was undertaken at the Jordan University Hospital during the period from June 2008 to July 2009. All patients undergoing tonsillectomy were randomly divided into two matched groups on alternating basis: group A included patients who received antibiotics (amoxicillin with clavulanic acid) for 5 days in the post-tonsillectomy period and group B included patients who received none. The two groups were compared with respect to fever, secondary bleeding, throat pain, and the time to resume to normal diet. Bleeding was more common in group A (5.5 %) than in group B (2 %). The average duration of throat pain was 4.2 days in group A, while it was 3.9 days in group B. The average time to resume normal diet was 5.7 days in group A, whereas it was 5.3 days in group B. Fever was noted in 17 (31 %) patients from group A, while it was observed in 15 (30 %) patients from group B. The use of antibiotics in the post-tonsillectomy period does not reduce post-operative morbidity in children and therefore it is advised to use antibiotics on an individual basis rather than routinely for patients undergoing tonsillectomy.