PURPOSE: Although one proposed solution to the problem of fatigued medical trainees is the implementation of work hours regulations, concerns about the effectiveness of these regulations are growing. Canada remains one of the few Western jurisdictions without legislated regulation. Recent research suggests that fatigue is a complex social construct, rather than simply a lack of sleep; thus, the authors explored how regulations and fatigue are understood in countries with established work hours frameworks to better inform other jurisdictions looking to address trainee fatigue. METHOD: Using constructivist grounded theory methodology, the authors conducted individual, semistructured interviews in 2015–2016 with 13 postgraduate medical trainees from four European countries with established work hours regulations. Data collection and analysis proceeded iteratively, and the authors used a constant comparative approach to analysis. RESULTS: Trainees reported that they were commonly fatigued and that they violated the work hours restrictions for various reasons, including educational pursuits. Although they understood the regulations were legislated specifically to ensure safe patient care and optimize trainee well-being, they also described implicit meanings (e.g., monitoring for trainee efficiency) and unintended consequences (e.g., losing a sense of vocation). CONCLUSIONS: Work hours regulations carry multiple, conflicting meanings for trainees that are captured by three predominant rhetorics: the rhetoric of patient safety, of well-being, and of efficiency. Tensions within each of those rhetorics reveal that managing fatigue within clinical training environments is complex. These findings suggest that straightforward solutions are unlikely to solve the problem of fatigue, assure patient safety, and improve trainee well-being.