ABSTRACT Issues related to portfolio development and use in assessing language learning in foreign language education are discussed. Among the issues are “audiences” and “purposes” of the portfolio. With teachers involved in an evaluation project of less commonly taught languages (Japanese, Chinese, Korean, and Russian) representing different educational levels (elementary and secondary), we collaborated in the design and implementation of student portfolios to examine growth in foreign language proficiency. The contents of portfolios were analyzed to determine their usability as a means of assessing foreign language learning. Analysis of the portfolios showed that many factors should be considered by teachers in deciding on contents and objectives of the portfolio. We conclude with a series of recommendations for foreign language educators interested in using portfolios to document their students' language learning progress.