Problem statement and background: Feedback is essential to learning and practice improvement, yet challenging both to provide and receive. The purpose of this paper was to explore reflective processes which physicians described as they considered their assessment feedback and the perceived utility of that reflective process. Methods: This is a qualitative study using principles of grounded theory. We conducted interviews with 28 family physicians participating in a multi-source feedback program and receiving scores across the spectrum from high to low. Results: Feedback, especially negative feedback, evoked reflective responses. Reflection seemed to be the process through which feedback was or was not assimilated and appeared integral to decisions to accept and use the feedback. Facilitated reflection upon feedback was viewed as a positive influence for assimilation and acceptance. Conclusions: Receiving feedback inconsistent with self-perceptions stimulated physicians' reflective processes. The process of reflection appeared instrumental to feedback acceptance and use, suggesting that reflection may be an important educational focus in the formative assessment and feedback process.