Medication administration errors can threaten patient outcomes and are a dimension of patient safety directly linked to nursing care. Children are particularly vulnerable to medication errors because of their unique physiology and developmental needs. This descriptive study surveyed a convenience sample of 57 pediatric and 227 adult hospital nurses regarding their perceptions of the proportion of medication errors reported on their units, why medication errors occur, and why medication errors are not always reported. In this study, which focuses on pediatric data, pediatric nurses indicated that a higher proportion of errors were reported (67%) than adult nurses indicated (56%). The medication error rates per 1,000 patient-days computed from actual occurrence reports were also higher on pediatric (14.80) as compared with adult units (5.66). Pediatric nurses selected distractions/interruptions and RN-to-patient ratios as major reasons medication errors occurred. Nursing administration's focus on the person rather than the system and the fear of adverse consequences (reprimand) were primary reasons selected for not reporting medication errors. Results suggest the need to explore both individual and systematic safeguards to focus on the reported causes and underreporting of medication errors.