This single case study examined how one inner city high school math teacher used e-portfolio assessment in an inclusive classroom setting. Specifically, it describes the teacher's perceptions and use of e-portfolio assessment, and its relationships to curricular content, as well as how the relationships among e-portfolio assessment, curricular content, and instruction varied for students with and without IEPs. Data were collected using semi-structured interviews, participant and passive observation, document/artifacts analysis, and field notes. Data collection and analysis occurred simultaneously. Coding was used in the final analyses. The results reveal e-portfolio assessment was defined by the fusion of its purpose, creation, selection of activities, and ongoing development. Overall, e-portfolio assessment benefited the teacher and his students. Students' e-portfolio entries helped the teacher identify conceptual understandings and errors, respond by re-teaching or clarification, and reflect on the efficacy of his instruction. E-portfolios also enhanced students' motivation, provided students with a more flexible work environment, and allowed students to easily edit their reflections as they grasped clarified concepts. Students with IEPs needed additional support in editing and learning the concepts being taught. Barriers related to using e-portfolio assessment were teacher time, computer accessibility, digitalization, and situational factors. The meaning of the results and the implications for practice and future research are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]