Discharge letters are crucial during care transitions from hospital to home. Research indicates a need for improvement to increase quality of care and decrease adverse outcomes. These letters are often sent from the hospital discharging physician to the referring clinician, typically the patient's General Practitioner (GP) in the UK, and patients may or may not be copied into them. Relatively little is known about the barriers and enablers to sending patients discharge letters. Hence, the aim of this study was to investigate from GP, hospital professional (HP) and patient perspectives how to improve processes of patients receiving letters and increase quality of discharge letters. The study has a particular focus on the impacts of receiving or not receiving letters on patient experiences and quality of care.The setting was a region in the West Midlands of England, UK. The research aimed to recruit a minimum of 30 GPs, 30 patients and 30 HPs in order to capture 90 experiences of discharge communication. Participating GPs initially screened and selected a range of recent discharge letters which they assessed to be successful and unsuccessful exemplars. These letters identified potential participants who were invited to take part: the HP letter writer, GP recipient and patient. Participant viewpoints are collected through interviews, focus groups and surveys and will be "matched" to the discharge letter sample, so forming multiple-perspective "quartet" cases. These "quartets" allow direct comparisons between different discharge experiences within the same communicative event. The methods for analysis draw on techniques from the fields of Applied Linguistics and Health Sciences, including: corpus linguistics; inferential statistics; content analysis.This mixed-methods study is novel in attempting to triangulate views of patients, GPs and HPs in relation to specific discharge letters. Patient and practitioner involvement will inform design decisions and interpretation of findings. Recommendations for improving discharge letters and the process of patients receiving letters will be made, with the intention of informing guidelines on discharge communication. Ethics approval was granted in July 2017 by the UK Health Research Authority. Findings will be disseminated in peer-reviewed journals, reports and newsletters, and presentations.