OBJECTIVE: To investigate whether certain patient, acute-care, or primary-care factors are associated with medication initiation and discontinuation in the community post-stroke or TIA. METHODS: Retrospective cohort study using prospective data on adult patients with first-ever acute stroke/TIA from the Australian Stroke Clinical Registry (April 2010 to June 2014), linked with nationwide medication dispensing and Medicare claims data. Medication users were those with ≥1 dispensing in the year post-discharge. Discontinuation was assessed among medication users and defined as having no medication supply for ≥90 days in the year post-discharge. Multivariable competing risks regression, accounting for death during the observation period, was conducted to investigate factors associated with time to medication discontinuation. RESULTS: Among 17,980 registry patients with stroke/TIA, 91.4% were linked to administrative datasets. Of these, 9,817 adults with first-ever stroke/TIA were included (45.4% female, 47.6% aged ≥75 years, and 11.4% intracerebral hemorrhage). While most patients received secondary prevention medications (79.3% antihypertensive, 81.8% antithrombotic, and 82.7% lipid-lowering medication), between one-fifth and one-third discontinued treatment over the subsequent year post-discharge (20.9% antihypertensive, 34.1% antithrombotic, and 28.5% lipid-lowering medications). Prescription at hospital discharge (sub-hazard ratio [SHR]: 0.70; 95% CI: 0.62-0.79), quarterly contact with a primary-care physician (SHR: 0.62; 95% CI: 0.57-0.67), and prescription by a specialist physician (SHR: 0.87; 95% CI: 0.77-0.98) were all inversely associated with antihypertensive discontinuation. CONCLUSIONS: Patterns of use of secondary prevention medications after stroke/TIA are not optimal, with many survivors discontinuing treatment within one-year post-discharge. Improving post-discharge care for patients with stroke/TIA is needed to minimize unwarranted discontinuation.