Background: Medicare and the Pharmaceutical Benefits Scheme may suggest to patients that medicines supply is the same everywhere in Australia. National Registration of Health Practitioners removed barriers to practitioners working interstate. Aim: To identify variations in state and territory medicines legislation with potential to negatively impact patients or practitioners. Method: Australian state and territory Acts and Regulations related to medicines prescribing and provision were compared. Legislative variations with potential to either harm patients, or increase health practitioners’ legal or ethical risk, were identified. Results: Potential patient harm may occur due to inconsistent requirements for prescription particulars, retention of prescription repeats by pharmacies in some states, or variation in age restriction on medicines provision. Potential practitioner risk may arise due to inconsistencies in practitioners’ prescribing rights or variable requirements to prescribe or dispense medicines. Conclusion: Ideally, all Australian states and territories should adopt uniform medicines legislation.