BackgroundTo estimate the extents of dosing variability in prescriptions of acetaminophen to children among pediatricians, family physicians and otolaryngologists.MethodsThe acetaminophen prescriptions in the systematic sampling datasets from the National Health Insurance Research Database in Taiwan were analyzed. The distribution of dosages was measured and expressed in terms of coefficient of variation (CV). The analyses were stratified by patient’s age, prescriber’s specialty and preparation form.ResultsFrom 13,868 prescribed items of acetaminophen in 2009, liquids accounted only for 11.1% (n = 1544). More than half (56.9%) of liquids were prescribed by pediatricians. The median dose (83.3 mg, n = 1683) of acetaminophen prescriptions in infants is around half of that in preschool children (166.7 mg, n = 3921), one-third in children (250.0 mg, n = 4926) and one-sixth in adolescents (500.0 mg, n = 3338). In infants, the prescriptions by pediatricians had the highest CV (86.7%), followed by family physicians (82.3%) and otolaryngologists (70.3%). The patterns were similar in preschool children and children, but the difference of CV among specialties narrowed down with the patient’s age.ConclusionsIn acetaminophen prescriptions to children, pediatricians had a wider variability of dosages and a higher ratio of liquid preparations than family physicians and otolaryngologists. Further investigations can be undertaken to estimate the accuracy of dosing variability as an indicator of prescribing quality. Besides, child-suitable drug preparations should be promoted to ensure patient safety.