Electronic prescribing systems (EPS) may be considered to enhance safe prescribing compared to paper-based prescribing systems. This thesis examined EPS safety, including in non-medical prescribers, in three studies. Firstly, a systematic review and meta-analysis examined the impact of EPS on the incidence of prescribing errors in hospital settings. EPS was associated with a reduction in prescribing errors based on a random effects model odds ratio (OR=0.26, 95% CI, 0.14 to 0.42, p˂0.00001). Secondly, prescribing errors detected and reported in hospital pharmacist interventions were examined. Errors were identified in 1.1% (95% CI 1.1 to 1.2%) of prescribed items. Most errors were considered significant (68.5%). Over half (56%) of errors occurred at the admission stage. Finally, a qualitative examination of semi-structured interviews was conducted with 23 medical and non–medical prescribers in a hospital. Prescribers described multiple contributory factors to electronic prescribing errors, including human factors and human-computer interactions. Prescribers’ perceptions of the benefits of EPS were clear, although concerns about overreliance on EPS and system complexity remained. Prescribers had useful suggestions to increase prescribing safety. In combination, the three branches of this thesis show EPS is an effective tool, and provides insights that can potentially optimise safe prescribing, including tailoring to end-user requirements.