Objective To observe the safety and effectiveness of dexmedetomidine (Dex) (nasal administration) combined with a small‑dose propofol (intravenous infusion) for children undergoing two‑position magnetic resonance imaging (MRI). Methods A total of 60 children, American Society of Anesthesiologists (ASA) grades Ⅰ or Ⅱ, who were scheduled for two‑position MRI examination (where the patients required to be moved once within more than 45 min) were enrolled. According to the random number table method, the patients were divided into two groups (n=30): a 2 μg/kg Dex (D2) group and a 3 μg/kg Dex (D3) group. Then, 20 min before MRI examination, patients in the D2 and D3 groups were nasally administered with Dex at 2 μg/kg and 3 μg/kg, respectively. During anesthesia induction, all the patients were administered with propofol at 1 mg/kg once, until Ramsay scores 5‒6 were achieved. The changes in vital signs before Dex administration (T0), 10 min after administration (T1), 20 min after administration (T2), after induction (T3), during examination (T4), after examination (T5), and on awakening (T6) and adverse reactions such as body movement, respiratory depression, decreased pulse oxygen saturation (SpO2) were recorded. The dosage of propofol, examination time and the awakening time were recorded and agitation during the recovery period and other complications were observed. Results There was no significant difference in mean arterial pressure (MAP) and SpO2 at all the time points between the two groups (P>0.05). Compared with those at T0, patients in both groups presented remarkably decreased heart rate at T3 (P=0.01), without statistical difference in heart rate at other time points. During examination, no children moved in the D3 group, while seven children moved in the D2 groups, without other adverse reactions in both groups (P<0.01). No statistical difference in the dosage of propofol between the two groups (P>0.05). While there was no statistical difference in examination time between the two groups, the D3 group presented remarkably longer recovery time than the D2 group (P=0.01). The incidence of agitation during the recovery period was 10% for both groups. Conclusions Intranasal administration of 3 μg/kg Dex plus intravenous infusion of a small‑dose propofol for children 20 min before two‑position NRI can obviously reduce the occurrence of body movement and improve examination efficiency, with high safety and comfort.