The purpose of this study was to investigate the factors affecting the unplanned peripheral intravenous reinsertion in pediatric inpatients at a teaching hospital in Taiwan. Researchers recruited 206 pediatric inpatients and their caretakers for the study and used multivariate regression in calculating their results. The results showed the following: whether pediatric patients received drugs (P < .001), whether the appropriate height of the drops was adhered to (P = .053), and whether the adjustment of the drip rate was done by the clients or caretakers themselves (P = .046) were significant determinants of unplanned peripheral intravenous reinsertions. It may be worthwhile to incorporate the findings regarding factors affecting the unplanned peripheral intravenous reinsertion into pediatric nurses' educational programs.