The ability to notice important events in a teaching situation and make decisions about these events is a key component of teaching well. Prospective teachers tend to notice more superficial aspects of classroom practice, such as class management. This article examines a video club in which four student teachers utilized the Mathematical Quality of Instruction (MQI) analysis framework to code each other's lessons and to discuss their coding in facilitated group sessions. We found that participants became better able to notice important aspect of mathematics more generally and MQI components more specifically. They also adopted a less evaluative stance toward what they noticed. Finally, their self-reported beliefs and practices altered; they credited their participation in the video club for their attempts to incorporate more opportunities for students to engage with mathematical content and ideas.