This study examined the nature of teaching expertise at the postsecondary level. Using the prototype view of teaching expertise set forth by Sternberg and Horvath (1995), which focuses on domain knowledge, efficiency, and insight, the teaching portfolios of 16 award-winning teacher educators from one of the largest colleges of education in the United States were examined. Specifically, reflective narratives were examined for the extent and variety of ways the features of the prototype model were represented and to determine whether critical features of teaching expertise were not included in the model. It was found that the data present a general picture which is consistent with many of the features of the Sternberg and Horvath model and supports a prototype conceptualization of teaching expertise. Eight of the ten features of expertise in the model were confirmed by the teachers in a variety of ways. The study also found evidence that affective dispositions, not included in the model, are an important factor among teacher educators. (MDM)