Background Prescribing errors are prevalent in hospital settings with feedback identified as one potential error reduction strategy. Hospital pharmacists work alongside prescribers at ward level and are credible facilitators of prescribing error feedback. A formalised programme of pharmacist-led prescribing error feedback was designed and implemented. Objective To determine the impact of the feedback intervention on prescribing error rates. Method Prospective prescribing audits were undertaken at baseline for control (n=11) and intervention group (n=10) prescribers. The intervention group received pharmacist-led, individualised constructive feedback on their prescribing, whilst the control group continued with existing practice. Prescribing was re-audited following 3-months of the intervention. Data were analysed using chi-squared and independent t-tests. Results Error frequency (123/641 intervention and 121/649 control) was comparable between groups at baseline (p = 0.819) with significant differences (90/1677 intervention and 236/984 control) post intervention (p = <0.005). Prescribing error rates were lower in the intervention group (mean change of -11.5%) and higher in the control group (mean change of +5.9%) following the intervention, with a mean significant difference of 17.4% (SD 4.7, 95% CI, -27.3 to –7.6), t = -3.694, p<0.05, between groups. Conclusion Pharmacist-led prescribing error feedback positively influences prescribing. This intervention shows promise for wider application in hospital settings to optimise patient safety.