Background and objectives Australian junior doctors are stressed and report high rates of burnout. The aim of this study was to understand the experience of burnout in general practice registrars and hospital equivalents. Methods Qualitative, semi-structured interviews were completed until saturation and thematically analysed. Results Stress was common among the interviewees, and the causes of stress were multifactorial. The junior doctors were aware of burnout prevention strategies but were not always effectively undertaking them. They were more likely to be feeling stressed when their expectations regarding workplace support were not met and when they believed they were practising beyond the level of their own abilities. Discussion On the basis of our findings, we propose a multifactorial model of junior doctor burnout. This model warrants further investigation to inform policies to reduce burnout in junior doctors and ensure a research-based solution is found to the progressive concerns regarding junior doctor burnout and suicides.