Abstract Background & Objectives: Inappropriate use of antibiotics in hospitals is a major problem. This study was done with the aim of determining impact of the educational intervention on adherence to guideline for antibiotic prophylaxis before surgeries in Alejalil hospital in Aq-Qala city,2012 Material and Method: This quasi experimental and one blind study was done on surgeons. Proportional of performed surgical by each physician, 125 records during the month before the intervention and 125 other surgical records after the intervention were selected. Information including indication, type of antibiotic, dose, time of administration of first dose and route of antibiotic administration based on patient records were compared with Ministry of Health guideline for antibiotic prophylaxis. The intervention consisted of meeting with surgeons and sending guideline to them. Data were analyzed using PASW18 software and Chi-square and Wilcoxon test. Results: Before the intervention, in 82.4% of surgeries and after the intervention, in 91.2% of surgeries, indication were correctly, also type of antibiotic (from 80% to 89.6%), dose (from 32% to 79.2%) and adherence to the guideline in all cases (from 32% to 79.2%) significantly had improved (P<0.05). The time and route of antibiotic administration before and after intervention was correct for all patients. Conclusion: Interventions based on Managed Care guidelines on the proper administration of antibiotics were effective. It is suggested that educational interventions planned in collaboration with physicians occurred to improve antibiotic prescribing.