Background/aim: In this study, we aimed to compare the effects of propofol-ketamine and propofol-fentanyl sedations on postprocedure nausea-vomiting in children undergoing magnetic resonance imaging (MRI). Materials and methods: This study included 100 pediatric patients (2–10 years old) who had propofol-ketamine and propofol-fentanyl for sedation to undergo MRI. The patients were divided into two groups, and sedation was performed through propofol-ketamine (Group K; n = 50) or propofol-fentanyl (Group F; n = 50). For sedation induction, intravenous (IV) bolus of 1.2 mg/kg propofol and 1 mg/kg ketamine were administered in Group K, IV bolus of 1.2 mg/kg propofol, and 1 µg/kg fentanyl in Group F. All patients received 0.5 mg/kg IV bolus propofol in additional doses when the Ramsay Sedation Score (RSS) was below 4 for maintenance. Perioperative heart rate, systolic arterial pressure, peripheral oxygen saturation, respiratory rate, and nausea-vomiting scores were recorded for each patient. Results: There was no difference between the groups in terms of nausea incidences at the 1st hour. However, the rate of vomiting was significantly higher in Group K. Conclusion: In our study, we showed that the vomiting rate was higher in the 1st hour in Group K compared to Group F.Key words: Magnetic resonance imaging, child, ketamine, fentanyl, deep sedation, propofol