Abstract The purpose of this study is to evaluate the drug utilization trends and to describe the prevalence and type of medication-related prescribing errors in infants treated at primary care health centers in Bahrain. Prescriptions issued for infants were collected over a 2-week period in May 2004 from 20 health centers. Prescribing errors were classified as omission (minor and major), commission (incorrect information) and integration errors. Medications were classified according to the British National Formulary. In infants with a mean age of 6.5 months (±3.1) drugs per prescription were 2.52 (±1.1). Paracetamol and sodium chloride nasal drops were the topmost prescribed systemic and topical drugs, respectively. In 2282 prescriptions, 2066 (90.5%) were with omission (major), commission, and integration errors. In 54.1% of prescriptions with omission errors, length of therapy was not specified in 27.7%, and in 12.8% the dosage form was not stated. In 43.5% of prescriptions with errors of commission, dosing frequency (20.8%) and dose/strength (17.7%)—related errors were most common. Errors of integration such as potential drug–drug interaction comprised 2.4% of all prescribing errors. The proportion of drugs prescribed irrationally were: contraindicated medications, notably chlorpheniramine, promethazine, and corticosteroids (16.1%); medications prescribed on a p.r.n. basis (13.3%); missed information regarding strength of medications (2.8%); medications prescribed over extended periods (2.7%); low dosing frequency (2.6%); supratherapeutic doses (2.3%); excessive dosing frequency (0.8%). Irrational drug therapy in infants, with prescribing errors were apparent in primary care practice, which may be related to a lack of drug information, pharmacovigilance programme, and nonadherence to basic principles of prescribing. Establishing a national drug policy and pharmacovigilance programme for promoting rational drug use are to be considered. There is also a need to evaluate the effectiveness of interventions by measuring the outcomes.