This study compared the effects of four electronic portfolio curricula on pre-service and beginning teachers' self-ratings of their professional development (n =207), using a 34 item electronic Portfolio Assessment Scale (ePAS). Three formative portfolios, A, C and D, had teacher development as a primary objective and used participants' narrative reflections on students over a 2-3 month period. One summative portfolio, B, assessed teacher accountability through participants' analyses of professional teaching standards concerning students during 1-2 week teaching units. Factor analyses of the ePAS assessments for each portfolio and all four combined yielded the same five factors concerning professional outcomes: overall teacher development, including reflective skill (F1), an understanding of assessment roles (F2), an understanding of backwards planning (F3), the benefit of analyzing student work (F4) and the benefit of teacher peer collaboration (F5). For F1, F3 and F5 the means of the formative portfolios A, C and D were significantly higher than those of portfolio B. No differences were found among the portfolios concerning the benefits of analyzing student work (F4). The researchers concluded that formative portfolios that focused on teacher development better supported professional outcomes than did the summative accountability portfolio. It was concluded that portfolios should not be used for the summative accountability of teachers.