Background: The UK medical education system faces a complex landscape of specialty training choices and heightenedcompetition. The Factors Affecting Specialty Training Preference Among UK Medical Students (FAST) study addresses the needto understand the factors influencing UK medical students'specialty choices, against a backdrop of increasing challenges inhealth care workforce planning. Objective: The primary objectives of the FAST study are to explore UK medical students'preferred specialties and the factorsthat influence these choices. Secondary objectives are to evaluate students'confidence in securing their chosen specialty, tounderstand how demographic and academic backgrounds affect their decisions, and to examine how specialty preferences andconfidence levels vary across different UK medical schools.Methods: A cross-sectional survey design will be used to collect data from UK medical students. The survey, comprising 17questions, uses Likert scales, multiple-choice formats, and free-text entry to capture nuanced insights into specialty choice factors.The methodology, adapted from the Ascertaining the Career Intentions of UK Medical Students (AIMS) study, incorporatesadjustments based on literature review, clinical staff feedback, and pilot group insights. This approach ensures comprehensiveand nondirective questioning. Data analysis will include descriptive statistics to establish basic patterns, ANOVA for groupcomparisons, logistic regression for outcome modeling, and discrete choice models for specialty preference analysis. Results: The study was launched nationally on December 4, 2023. Data collection is anticipated to end on March 1, 2024, withdata analysis beginning thereafter. The results are expected to be available later in 2024. Conclusions: The FAST study represents an important step in understanding the factors influencing UK medical students'career pathways. By integrating diverse student perspectives across year groups and medical schools, this study seeks to providecritical insights into the dynamics of specialty, or residency, selection. The findings are anticipated to inform both policy andeducational strategies, aiming to align training opportunities with the evolving needs and aspirations of the future medicalworkforce. Ultimately, the insights gained may guide initiatives to balance specialty distribution, improve career guidance, andimprove overall student satisfaction within the National Health Service, contributing to a more stable and effective health caresystem