The purpose of this study was to examine how teacher attitudes toward online learning in K-12 education vary before, during, and after participation in a professional development program focused on ePedagogy and online course development. The study also examined which Key Design Factors, as identified by Wells (2007), influence teachers' attitudes toward online learning in K-12 education. This study utilized a one-group, repeated measures design. Attitudes from 27 K-12 educators were measured using the Online Learning Attitude Scale (OLAS) adapted from an instrument developed by MacArthur, Wang, & Crosby (2003) and modified in a further study by Uzunboylu (2007). Data was collected from the OLAS at three points during a professional development program. The data was analyzed within-subjects and between-subjects. Within-subjects data analyzed how attitudes in the aggregate varied before, during, and after the professional development program. Between-subjects data compared attitudes based upon previous experience with online learning and years of teaching experience. The results of this study revealed that teacher attitudes toward online learning in K-12 education did not vary before, during, and after participation in a professional development program focused on ePedagogy and online course development with one exception. Significant results were found among participants with 9-13 years of teaching experience. All five Key Design Factors were included in the program and may have influenced the score improvements in the group with teaching experience from 9-13 years. [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/en-US/products/dissertations/individuals.shtml.]