Introduction: Clinicians treating human immunodeficiency virus (HIV) patients are expected to stay up-to-date with rapidly changing knowledge and practice. Continuing medical education (CME) programs are one source of new knowledge about HIV clinical management. Little is known about instructor-participant discourse in HIV CME programs and whether or how instructors model their decision-making strategies. Methods: Discussions about clinical cases between instructors and participants in attendance at a HIV CME program were videotaped, transcribed, segmented, and coded, focusing on the participants' questions and the instructor's responses. Results: Twenty-four case studies involving four instructors and 45 participants (54% infectious disease clinicians and 46% general practitioners) were analyzed. Five case studies are presented herein to illustrate how the instructors use the participants' questions and case studies to model cognitive processing and decision making in HIV treatment practice. Discussion: This article provides a model of interactive and practice-based teaching discourse in the context of an HIV CME activity. Throughout this discourse the instructors model the fluent use of representations for the CME learners and provide a safe environment where participants can share their misunderstandings. (Contains 5 tables and 1 figure.)