In this paper the authors examine the uses of teaching performance assessments (TPAs) as resources for learning, program evaluation, and improvement in teacher education. The authors begin by outlining their conceptual framing and related research questions about the uses of TPAs as resources for program evaluation and improvement. They describe some of the defining features and affordances of TPAs and consider how these measures engage traditional questions and concerns about the validity and generalizability of the findings they yield. The discussion then proceeds with a brief history of teaching portfolios, locally developed performance assessments, and standardized measures of teaching performance, noting how the purposes of these assessments have been shaped by the increasing emphasis on external accountability in public policy over recent decades. Using this historical account as context, the authors focus the main body of their review on the contemporary research literature related to the uses of standardized TPAs in preservice teacher education. They conclude the paper with a set of recommendations for policy, practice, and research aimed at evaluating and improving the uses of TPAs as resources for the improvement of teacher education.