The purpose of this American study was to examine student teachers' ability to make instructional decisions as they engaged in teaching. We examined the narrative accounts provided by 150 student teachers within their teacher work samples (TWSs). Results indicated that most student teachers were able to implement some aspects of instructional decision making, such as noting a specific difficulty with student learning and making an on-the-spot adjustment in their instruction. However, other elements of instructional decision making were less likely to be implemented. For example, student teachers relied on a limited range of formative assessment strategies and instructional modifications, and very few provided a sound rationale for their choice of modification. These results suggest that novice teachers may benefit from more opportunities to reflect and critique upon authentic learning experiences as they complete their teacher preparation programs. Finally, the TWS appears to represent a viable method for examining the instructional decisions of student teachers. (Contains 1 figure and 2 tables.)