Background Anxiety and fear frequently causes an aversion to applying a face mask and increases difficulty during pediatric induction.There is at present little study of this problem.Therefore,the aim of this study was to investigate the effect of the combination of mask preconditioning and midazolam pretrealment on mask acceptance during pediatric induction and on postoperative mask fear.Methods One hundred and sixty children were randomly assigned into four groups:the mask preconditioning group (MaG),the midazolam pretreatment group (MiG),the mask/midazolam combination group (Ma/MiG),and the saline group (SaG).The Modified Yale Preoperative Anxiety Scale (m-YPAS) was employed to assess the anxiety in the operation room (OR).A Mask Acceptance Score (MAS) was measured during inhalational induction and the incidence of mask fear (MAS ≤2) was evaluated postoperatively.Results The MaG and Ma/MiG groups had the highest mask acceptance scores but there were no differences between these two groups (P ＜0.05).The average anxiety level of children entering the OR was much lower in the MaG and Ma/MiG groups than in the SaG group (P ＜0.05).During induction,the anxiety level increased in the SaG and MaG groups but decreased in the MiG and Ma/MiG groups (P ＜0.05).At the postoperative third day,the incidence of mask fears was as high as 23％ in the SaG group,15％ in the MiG group,but only 2.5％ in the MaG and Ma/MiG groups.Conclusions The single use of mask preconditioning has a better influence than midazolam for increasing mask acceptance during inhalational induction and reducing postoperative mask fear,reducing the anxiety level during induction,improving induction compliance and shortening the total mask time.A mask preconditioning and midazolam combination did not increase mask acceptance during inhalational induction,reduce mask fears postoperatively,improve induction compliance,nor shorten the total mask time.But it can better reduce the anxiety level during induction.