This study reports on a district-wide research-based professional development (PD) that included 207 teachers and administrators. Data were collected from pre/post surveys, content analysis of the participants' wiki pages, and a follow-up questionnaire. Findings indicate that participants significantly improved their foundational and technical wiki skills. The PD had a significant impact on participants' perceptions of preparedness to use wikis in the classroom. Findings provided evidence that research-based PD can foster sustained teacher practice. The study demonstrates that participation in PD that is sustained, student-centered, participatory, and supported by adequate resources can have a significant impact on teacher learning and practice about specific technologies. (Contains 2 tables.)