Relational reasoning, which has been defined as the ability to discern meaningful patterns within any informational stream, is a foundational cognitive ability associated with education, including in scientific domains. This study entailed the analysis of instructional conversations in which an attending clinical neurologist and his team of residents made diagnostic and therapeutic decisions about actual patients in a hospital setting. The primary goal was to investigate the role of 4 manifestations of relational reasoning (i.e., analogy, anomaly, antinomy, and antithesis) in medical education and diagnostic and therapeutic decision making. Results indicated that the degree to which members of the medical team used the 4 forms of relational reasoning depended on their role and expertise, as well as the time point in the problem-solving process. Specific reasoning patterns that emerged in the discourse and a prototypical model of the reasoning process are described and implications for research and practice are considered.