Background: Late side effects of head and neck cancer treatment commonly affect swallowing function. Late radiation-associated dysphagia (late-RAD) often presents years post-treatment when patients have been discharged from their multidisciplinary team. Timely symptom management may provide important physical and emotional support, potentially reducing the overall healthcare burden. Speech and language therapists (SLTs) are key in the assessment and management of dysphagia but there is no current guidance in the late-RAD setting. Aims: The primary objective was to establish how late-RAD is assessed in both existing literature and by UK SLT. The study also aimed to explore UK SLT approaches to management. Methods: A dual methodology approach was taken. A scoping review (SR) of PubMed, Scopus, CINAHL, Web of Science and Embase databases was conducted between November and December 2022. Eligibility criteria included studies reporting dysphagia outcomes >2 years post-treatment with narrative data synthesis. Also, a survey of SLTs working in the United Kingdom was conducted between November 2023 and February 2024. Respondents were questioned about their current pathways and service provision for patients with late-RAD. Main Contribution: The SR included 39 studies. Dysphagia was assessed using three different toxicity grades; five patient-reported outcome measures (PROMs) and five clinical assessments. Five studies were multidimensional in their approach to data collection, whilst nine used PROMs alone and four used a toxicity grade alone. The survey received 56 responses. Only six respondents reported an existing late effect clinic (all tumour sites) in their region. A wide range of measures were used to assess dysphagia including 12 different PROMs. Instrumental assessments were used by most (98% Videofluoroscopy; 82% Fibreoptic Endoscopic Evaluation of Swallowing). Rehabilitation was offered by 86% and this was intensive in 34%. Late-RAD patient information was routinely provided by 35 respondents and usually within 1 year of treatment completion. Conclusion: A wide range of assessment methods and outcome measures were used to report dysphagia in existing literature but often in a unidimensional approach. In the United Kingdom, SLTs also use a variety of assessment tools and regularly offer intensive rehabilitation. Without consensus on how we measure late-RAD, synthesising evidence to guide service provision is challenging.