Objective This study evaluated whether frequent (fortnightly) audit and feedback cycles over a sustained period of time (>12 months) increased clinician adherence to recommended guidelines in acquired brain injury rehabilitation. Design A before and after study design. Setting A metropolitan inpatient brain injury rehabilitation unit. Participants Clinicians; medical, nursing and allied health staff. Interventions Fortnightly cycles of audit and feedback for 14 months. Each fortnight, medical file and observational audits were completed against 114 clinical indicators. Main outcome measure Adherence to guideline indicators before and after intervention, calculated by proportions, Mann-Whitney U and Chi square analysis. Results Clinical and statistical significant improvements in median clinical indicator adherence were found immediately following the audit and feedback program from 38.8% (95% CI 34.3 to 44.4) to 83.6% (95% CI 81.8 to 88.5). Three months after cessation of the intervention, median adherence had decreased from 82.3% to 76.6% (95% CI 72.7 to 83.3, p<0.01). Findings suggest that there are individual indicators which are more amenable to change using an audit and feedback program. Conclusion A fortnightly audit and feedback program increased clinicians’ adherence to guideline recommendations in an inpatient acquired brain injury rehabilitation setting. We propose future studies build on the evidence-based method used in the present study to determine effectiveness and develop an implementation toolkit for scale-up.