Health care received in health facilities depends on adequate consultation, correct prescription and dispensing with relevant information given to the patient. These are some of the indicators for rational drug use. The objective of the study was to determine the pattern of prescription among prescribers in twenty Primary Health Care Centers of Lagos State using some of these indicators used in investigating health facilities by the World Health Organisation and International Network for Rational Use of Drugs. The study was carried out using multi-stage random sampling in selecting the Primary Health Care Centers from each of the twenty Local Government Areas of Lagos State. Both prospective and retrospective data were collected and analysed using Epi-Info version 6. The results showed that there was polypharmacy, misuse of antibiotics and injections. There was no statistically significant difference between the retrospective and prospective indicators of mean drugs prescribed per encounter, percentage antibiotics prescribed and percentage of generic prescription. It was concluded that there was irrational prescription pattern in all the selected health facilities as evidenced by poly-pharmacy, misuse of antibiotics and low generic prescriptions. There is need for educational intervention to improve the prescribing habits of health professionals in these health facilities.