This study sought to understand the impact of self-efficacy and professional development on the implementation of specific Web 2.0 tools in the elementary classroom. There were three research questions addressed in this QUAN-Qual study. Quantitative data were collected through three surveys with 48 total participants: the Web 2.0 tools Utilization Instrument (Pan & Franklin, 2011), the Web 2.0 Utilization Self-Efficacy Instrument (Pan & Franklin, 2011), and the Standards Assessment Inventory 2 (Learning Forward, 2011). Qualitative data were collected through Sadaf's (2013) Interview Protocol with two focus groups. The first research question answered to what degree do elementary teachers report utilization of specific Web 2.0 tools. The WTII found that the majority of teachers were implementing Web 2.0 tools. Of those implementing Web 2.0 tools, the majority were doing so on a monthly basis. Through Spearman's Correlation, the relationship between self-efficacy, and the utilization of specific Web 2.0 tools, a strong positive correlation was established (Research Question 2). There was a weak positive correlation between self-efficacy and professional development through the computation of Spearman's correlation (Research Question 3). In post hoc research and Spearman's Correlation, there was a weak negative correlation between the number of years teaching and self-efficacy. There was also a weak negative correlation between the number of years teaching and the utilization of specific Web 2.0 tools. Self-efficacy had the strongest relationship to the utilization of specific Web 2.0 tools. Therefore, a two-fold approach to professional development would be most effective for increasing Web 2.0 utilization. Professional development opportunities would be most effective attempting to increase a teacher's technology self-efficacy while increasing their skills and knowledge on specific Web 2.0 tools. [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.]