Poor matriculation results in South African urban schools have resulted in the implementation of professional development programs for principals who wish to improve their qualifications and practice. This article studies principals' perceptions of the efficacy of using portfolios to assess their professional growth. Using a poststructural lens to theorize portfolio use, interview data were examined to discern what themes consistently evolved when principals were engaged in self-evaluating their own professional practice through a methodological framework of portfolio development. The findings revealed insights into the efficacy of the use of professional portfolios in the professional development of principals. (Contains 2 notes.)