INTRODUCTION: Providing high-quality teaching to residents during attending rounds is challenging. Reasons include structural factors that affect rounds, which are beyond the attending's teaching style and control. OBJECTIVE: To develop a new evaluation tool to identify the structural components of ward rounds that most affect teaching quality in an internal medicine (IM) residency program. METHODS: The authors developed a 10-item Ecological Momentary Assessment (EMA) tool and collected daily evaluations for 18 months from IM residents rotating on inpatient services. Residents ranked the quality of teaching on rounds that day, and questions related to their service (general medicine, medical intensive care unit, and subspecialty services), patient census, absenteeism of team members, call status, and number of teaching methods used by the attending. RESULTS: Residents completed 488 evaluation cards over 18 months. This found no association between perceived teaching quality and training level, team absenteeism, and call status. We observed differences by service (P < .001) and patient census (P = .009). After adjusting for type of service, census was no longer significant. Use of a larger variety of teaching methods was associated with higher perceived teaching quality, regardless of service or census (P for trend < .001). CONCLUSIONS: The EMA tool successfully identified that higher patient census was associated with lower perceived teaching quality, but the results were also influenced by the type of teaching service. We found that, regardless of census or teaching service, attendings can improve their teaching by diversifying the number of methods used in daily rounds.