Aim: Narcotics may blunt agitataion in pediatric patients undergoing diagnostic procedures. The current study investigates the effect of intravenous (iv) fentanyl on agitation in pediatric patients undergoing magnetic resonance imaging (MRI). Materials and Methods: We studied 51 children (ASA I-II; ages: 18 months-10 years) undergoing MRI under sevoflurane anesthesia. Anesthesia was induce with 8% scvoflurane in 50% O2 and 50% N2O followed by 1.5-2% sevoflurane during maintenance. Patients were randomly divided into three groups: Group P (n=17) received 2 mL iv saline on induction and 10 min. before the end of the anesthesia group F (n=17) received 1μg kg-1 iv fentanyl on induction and 2 mL iv saline 10 min. before the end of the anesthesia Group Fe(n=17) received 2 mL iv saline on induction and 1Ig kg -1 iv fentanyl 10 min before the end of the anesthesia. The heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and oxygen saturation (SpO2) of the patients were monitored throughout the procedure. Recovery parameters including time to spontaneous eye-opening, eye-opening for verbal commands, extubation, and upper and lower limb movement were recorded. Agitation scores were measured every 5 minutes for 25 minutes. Prolonged agitation was defined as agitation score over 4, observed during two or more consecutive mesurements. Procedure and anesthesia, duration and perioperative and postoperative side effects were recorded. Results: Agitation was significantly higher in Group P than in Group Fi and Group Fe (47.1%, 11.8%, 5.9%, respectively) (p=0.007). Prolonged agitation was observed in 5 cases in Group P; in 1 case in Group Fi, and none in Group Fe (29.4%, 5.9%, 0%, respectively) (p=0.009). The recovery characteristics were similar between groups. Conclusion: We conclude that fentanyl administered in low doses at induction or before emergence from sevoflurane anesthesia for MRI, is safe and reduces emergence agitation.