1. Poor prescribing is probably the most common cause of preventable medication errors in hospitals, and many of these events involve junior doctors who have recently graduated. Prescribing is a complex skill that depends on a sound knowledge of medicines, an understanding of the principles of clinical pharmacology, the ability to make judgements concerning risks and benefits, and ideally experience. It is not surprising that errors occur. 2. The challenge of being a prescriber is probably greater now than ever before. Medical education has changed radically in the last 20 years, reflecting concerns about an overburdened curriculum and lack of focus on social sciences. In the UK, these changes have resulted in less teaching in clinical pharmacology and practical prescribing as guaranteed features of undergraduate training and assessment. There has been growing concern, not least from students, that medical school training is not sufficient to prepare them for the pressures of becoming prescribers. Similar concerns are being expressed in other countries. While irrefutable evidence that these changes are related to medication errors identified in practice, there is circumstantial evidence that this is so. 3. Systems analysis of errors suggests that knowledge and training are relevant factors in causation and that focused education improves prescribing performance. We believe that there is already sufficient evidence to support a careful review of how students are trained to become prescribers and how these skills are fostered in the postgraduate years. We provide a list of guiding principles on which training might be based.