The portfolio, a collection of a student's work over their course of study, has become a popular tool for college teaching. Portfolios have the distinct advantage of engaging the learner in reflection (Reis & Villaume, 2002; Willis & Davies, 2002) and self-assessment (Hill, 2002), while at the same time creating documentation useful for programmatic assessment and program review. As the portfolio movement grows, new questions arise regarding how to effectively integrate portfolios into teacher education programs. This article discusses best practice as it relates to portfolio implementation in teacher education. Major challenges for educators are highlighted. These include issues such as engaging the student learner, determining portfolio content, and assessment.