We have identified deficiencies in medical students' drug administration skills, and we attempted to address them with interactive online teaching modules and simulated critical incident scenarios. Short-term improvements have been evident with this intensive effort, but medium-term retention of skills has not been measured. A drug administration lecture, an online module and a simulated emergency scenario were offered to final year clinical students. None of the teaching was compulsory but participation was recorded, along with students' simulator performances and marks in an objective structured practical examination 9 months later. A poor simulator score predicted a poor performance in the later examination. Participation in the simulated scenario only significantly improved examination scores when supplemented by online teaching (p = 0.002). Intensive drug administration teaching using an online module and high fidelity simulation improves drug administration skills in the medium term. Students found simulation much more engaging than online teaching. Our research focuses on drug administration skills, originating from our observation that medical students and doctors are confused by expressing the concentration of drug solutions as ratios and percentages rather than mass concentration [1][2][3]. These findings concur with other researchers [4][5][6][7] and, despite calls for ampoule labelling to be standardised [8], drugs are still presented in packaging that is potentially confusing.Our findings have also suggested that a lack of education about drug administration can lead to drug dosing errors, and served to highlight that drug administration skills in our university were taught on an entirely ad hoc basis [1]. We sought to improve drug administration teaching for our medical students by ensuring that drug dose calculation was included in formal teaching for all students. Traditional teaching was complemented by an interactive online teaching module, which improved students' performances in drug administration questions in end of attachment assessments and final examinations [9]. We went on to examine how better teaching might influence the acquisition of practical skills using students' performance in a simulated critical incident as an outcome measure.We conducted a randomised, controlled trial in a high fidelity patient simulator that showed that additional online teaching also improved medical students' practical skills in a simulated emergency scenario [10]. Students were randomly allocated into two groups: one group was invited to view the additional teaching before their simulated scenario, the other group received the invitation afterwards. Students who had viewed the teaching beforehand were found to have performed significantly