This paper describes how teacher portfolios could be used to provide teachers with the opportunity to grow professionally in concert with other teachers and in ways that promote school, district, and professional student performance standards. An opening section discusses the lack of progress in developing effective teacher evaluation and improvement procedures in recent years. A discussion of portfolio use argues that it can encourage collegiality and collaboration; experimentation; incorporation of available knowledge bases; involvement in goal setting, implementation, evaluation, and decision-making; time to work on staff development and assimilate new learning; leadership and sustained administrative support; incentives and rewards; designs built on principles of adult learning; and integration of individual goals with school and district goals. A list of what to include in a portfolio suggests statement of goals and philosophy of teaching; summary of professional responsibilities and involvements; criteria for assessing teaching performance; and criteria for assessing service to school and the profession. It is concluded that portfolios allow for teachers to be in the middle of current efforts to improve the quality of teaching and learning in the schools. Contains 32 references. (JB)