Aim: The purposes of this study were (i) to evaluate pediatric nurses' knowledge of pharmacology, and (ii) to analyze known pediatric administration errors. Background: Medication errors occur frequently and ubiquitously, but medication errors involving pediatric patients attract special attention for their high incidence and injury rates. Methods: A cross-sectional study was conducted. A questionnaire with 20 true-false questions regarding pharmacology was used to evaluate nurses' knowledge, and the known pediatric administration errors were reported by nurses. Findings: The overall correct answer rate on the knowledge of pharmacology was 72.9% (n=262). Insufficient knowledge (61.5%) was the leading obstacle nurses encountered when administering medications. Of 141 pediatric medication errors, more than 60% (61.0%) of which were wrong doses, 9.2% of the children involved suffered serious consequences. Conclusions: Evidence-based results demonstrate that pediatric nurses have insufficient knowledge of pharmacology. Such strategies as providing continuing education and double-checking dosages are suggested.