The purpose of this study was to examine the relationship between factors (internal [personal] and external [environmental]) and teachers' participation in professional development (PD) programs in Turkey. The researcher employed a survey design, using a multiple-stage sampling method, selecting 30 out of 66 elementary schools in the Center district of Osmaniye, Turkey. All teachers present on the day of the survey administration were invited to participate in the study. The total number of returned, usable surveys was 525 out of 600 total questionnaires. After analyzing the collected data using Poisson regression, the researcher found that although age, teachers' attitudes towards PD activities, time, funding, and colleague influence affect teachers' participation in PD activities in statistically significant ways; gender, teaching experience, grade level of teaching, education level, teachers' self-efficacy, principal, and school culture do not affect their participation in these activities in Turkey. [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.]