GP trainee antibiotic prescribing is higher than justified by guidelines. Understanding factors contributing to this pattern will assist in developing educational interventions to improve evidence-based prescribing habits during the early stages of these doctors' careers.

A multifaceted intervention reduced antibiotic prescribing for bronchitis/bronchiolitis but not URTIs.

These findings suggest GP trainees find skin problems challenging and may indicate a need for more and better targeted undergraduate and GP trainee education.

The high frequency of antibiotic prescribing and the lack of attenuation in prescribing with increased experience suggest current educational interventions and the apprenticeship model of training is not fostering appropriate practice in this important clinical area. Targeted educational interventions, for supervisors as well as trainees, are indicated.

Trainees gain reasonably broad exposure overall in terms of patient demographics and problems managed. In comparison to established GPs, trainees managed the same mean number of problems, but the nature of problems managed was different, with more new patients, more new problems and less chronic disease. Our findings have significant implications for GP training in Australia.