BACKGROUND: Ward attending rounds are fundamental for internal medicine residency training. An improved understanding of interns' and residents' perceptions of attending rounds should inform training programs and attending physicians. OBJECTIVES: The aim of this study was to assess residents' perceptions of successful attending rounds. DESIGN: We convened two groups of interns and two groups of residents, to elicit their perceptions on attending rounds. SUBJECTS: Participants were recruited by e-mail and conference announcements from the 49 interns and 80 residents in the internal medicine and medicine-pediatrics residency programs. MEASUREMENTS: The nominal group technique (NGT) uses a structured group process to elicit and prioritize answers to a carefully articulated question. MAIN RESULTS: Seven interns (14%) identified 27 success factors and ranked attending approachability and enthusiasm and high quality teaching as most important. A second group of six (12%) interns identified 40 detractors and ranked having "mean attendings," receiving disrespectful comments, and too long or too short rounds as the most significant detractors. Nine (11%) residents identified 32 success factors and ranked attention to length of rounds, house staff autonomy, and establishing goals/expectations as the most important success factors. A second group of six (8%) residents identified 34 detractors and ranked very long rounds, interruptions and time constraints, and poor rapport between team members as the most significant detractors). CONCLUSIONS: Although there was some overlap in interns' and residents' perceptions of attending rounds, interns identified interpersonal factors as the most important factors; whereas residents viewed structural factors as most important. These findings should assist attending physicians improve the way they conduct rounds targeting both interns and residents needs.