Purpose: The purpose of this study is to understand how, when, and why emergency medicine residents learn while working in the chaotic environment of a hospital emergency room. Design/methodology/approach: This research used a qualitative interview methodology with thematic data analysis that was verified with the entire population of learners. Findings: Analysis of the data revealed four different types of learning episodes, each with facilitating factors. The episodes varied in intensity, duration, and the degree of motivation and self-direction required of the learner. One episode could prompt another. Learning occurred both individually and in social interaction in the workplace during the episode, as well as outside of the workplace environment after the experience had occurred. Research limitation/implications: Recommendations for individuals to maximize their learning related to this chaotic work environment are identified, along with associated implications for their trainers. These suggestions advocate for current apprenticeship approaches to training to include a developmental perspective, providing effective feedback and supporting learner self-assessment and reflection. Originality/value: This paper makes an original contribution to the literature by describing the process of learning by emergency medicine residents in the chaotic work setting of an emergency department. The paper also expands understanding of the types of learning episodes and the factors that contribute to their occurrence. Finally, the research illustrates how the voice of the learners can be used to inform their training. (Contains 1 figure and 5 tables.)