This article discusses the benefits of professional portfolios for educational diagnosticians throughout their careers as a means of documenting proficiency and experience in communication, assessment, time management, organization, community resources, and educational planning. Various purposes of the portfolio are considered; for gaining employment, as a tool for informing performance evaluations, for supporting professional growth and development throughout the career, along with differences in the nature of the portfolio according to its purpose. The article also addresses the possible contents, organization, and format of the educational diagnostician's portfolio. (Contains 2 figures and 2 tables.)