Formative feedback, given in an ongoing fashion during the learning process, is fundamental to clinical education. However, dissatisfaction with formative feedback among residents is common. Difficulties with formative feedback are intensified in the operating room (OR) setting due to fast pace, space limitations, and frequent rotation of residents and attendings. In the anesthesiology and critical care department at the University of Pennsylvania Perelman School of Medicine, the authors launched the Feedback Moment initiative from January 2018 to May 2018 in which 24 first-year residents and attendings were given a short series of prompts designed to facilitate regular, high-quality formative feedback. The authors conducted semistructured interviews with residents before and after the initiative to evaluate its impact. In baseline interviews, 18 participating residents stressed the importance of formative feedback but described feeling unsure of their performance due to lack of ongoing constructive input from attendings. They felt hesitant to approach attendings for feedback due to a desire not to interrupt OR workflow or appear incompetent. In follow-up interviews, residents described the initiative as helping to normalize constructive formative feedback but difficult to execute regularly due to OR workflow issues and frequent rotation of attendings with varying approaches. Challenges faced by participants in this initiative highlight several considerations for effective OR-based formative feedback. Alternative timings for initiating feedback must be considered in light of the hectic nature of the OR workflow. Residents should be equipped with the skills necessary to adapt to varying practice patterns and frequent rotation between attendings, while attendings should be trained to provide a clear rationale for constructive feedback that allows residents to quickly adapt to practice variation. Finally, establishing clear goals among resident-attending pairs is critical to ensuring that formative feedback given in necessarily brief sessions is focused and productive.