ObjectiveTo evaluate the effectiveness of a preoperative tour to a simulated anaesthesia induction at operating theatre on reducing children’s and parents’ preoperative anxiety.DesignA pragmatic, single-centre, assessor-blinded, randomised controlled trial.SettingIn preoperative anaesthesia clinic and the operating room at a tertiary care centre in Saudi Arabia.ParticipantsOne hundred and sixteen children–parents dyads (pairs) (n=57) intervention group (IG); (n=59) control group (CG) with children aged 4–14 years who were planned for day case procedures under general anaesthesia.InterventionsParticipants’ dyads were randomly allocated through a computer to receive either a preoperative tour to a real operating theatre and simulate anaesthesia induction or standard of care.Main outcome measureThe primary study outcome was children’s anxiety levels as measured by the modified-Yale Preoperative Anxiety Scale (m-YPAS), and the parent’s anxiety level as assessed by the Beck Anxiety Inventory Scale. The children’s anxiety levels were measured at two time points, the preoperative holding area (T0) and before the anaesthesia induction (T1), and the parents’ anxiety level was measured after the anaesthesia induction. The secondary outcomes were the prevalence of preoperative anxiety and children’s somatic signs of anxiety including heart rate and systolic blood pressure.ResultsThe Mann-Whitney U test of m-YPAS scores showed significant differences in the children’s anxiety levels between the CG and IG at T0 (Z −5.009); p<0.01) and T1 (Z −6.599); p<0.01). BIAS analysis revealed a significant difference in the parents’ anxiety level between the CG and IG (Z −4.353); p<0.01). The prevalence of children’s anxiety was reported by 55 (93.2%) in the CG compared with 25 (43.9%) in the IG, with a statistically significant difference (p<0.001).ConclusionThe preoperative simulated anaesthesia induction was effective in reducing preoperative anxiety in children and their parents.