Background: Information about antibiotic prescribing practice in primary care is not available for Ireland, unlike other European countries. The study aimed to ascertain the types of antibiotics and the corresponding conditions seen in primary care and whether general practitioners (GPs) felt that an antibiotic was necessary at the time of consultation. This information will be vital to inform future initiatives in prudent antibiotic prescribing in primary care.Methods: Participating GPs gathered data on all antibiotics prescribed by them in 100 consecutive patients' consultations as well as data on the conditions being treated and whether they felt the antibiotic was necessary.Results: 171 GPs collected data on 16,899 consultations. An antibiotic was prescribed at 20.16% of these consultations. The majority were prescribed for symptoms or diagnoses associated with the respiratory system; the highest rate of prescribing in these consultations were for patients aged 15-64 years (62.23%). There is a high rate of 2nd and 3rd line agents being used for common ailments such as otitis media and tonsillitis. Amoxicillin, which is recommended as 1st line in most common infections, was twice as likely to be prescribed if the prescription was for deferred used or deemed unnecessary by the GP.Conclusion: The study demonstrates that potentially inappropriate prescribing is occurring in the adult population and the high rate of broad-spectrum antimicrobial agents is a major concern. This study also indicates that amoxicillin may be being used for its placebo effect rather than specifically for treatment of a definite bacterial infection.