Background: Antibiotic use has been beneficial and, when prescribed and taken correctly, their value in patient care is enormous. Over prescription and abuse of antibiotics in the treatment is a worldwide problem. More than 40% of children with acute diarrhea receive unnecessary antibiotics and up to 60% of children with acute upper respiratory tract infections receive antibiotics inappropriately. Objectives: To assess adherence of family physicians to guidelines for antibiotic prescription in acute upper respiratory tract infections and diarrhea in children under 5 years. Methods: A cross-sectional study was conducted in 4 randomly selected family health facilities in Alexandria governorate. An observation checklist was designed based on Integrated Management of Childhood Illness (IMCI) guidelines and used on a sample of 300 consultation sessions. Results: The study revealed that antibiotics were prescribed in 49.7% of the observed sessions and prescribed appropriately in 55.4% of the sessions according to IMCI guidelines. The type of prescribed antibiotic was appropriate in 91.8% of the sessions. Conclusion: Family physicians' antibiotics prescription is inappropriate in nearly half of the studied children.