BACKGROUND: Cognitive and mood problems have been highlighted as priorities in stroke research and guidelines recommend early screening. However, there is limited detail on the preferred approach.We aimed to (1) determine the optimal methods for evaluating psychological problems that pre-date stroke; (2) assess the test accuracy, feasibility and acceptability of brief cognitive and mood tests used at various time-points following stroke; (3) describe temporal changes in cognition and mood following stroke and explore predictors of change. METHODS: We established a multi-centre, prospective, observational cohort with acute stroke as the inception point - Assessing Post-stroke Psychology Longitudinal Evaluation (APPLE). We approached patients admitted with stroke or transient ischaemic attack (TIA) from 11 different hospital sites across the United Kingdom. Baseline demographics, clinical, functional, cognitive, and mood data were collected. Consenting stroke survivors were followed up with more extensive evaluations of cognition and mood at 1, 6, 12 and 18 months. RESULTS: Continuous recruitment was from February 2017 to February 2019. With 357 consented to full follow-up. Eighteen-month assessments were completed in September 2020 with permissions in-place for longer term in-person or electronic follow-up. A qualitative study has been completed, and a participant sample biobank and individual participant database are both available. DISCUSSION: The APPLE study will provide guidance on optimal tool selection for cognitive and mood assessment both before and after stroke, as well as information on prognosis and natural history of neuropsychological problems in stroke. The study data, neuroimaging and tissue biobank are all available as a resource for future research.