As a conceptual framework, professional learning communities (PLCs) have been described as a means to increase teacher effectiveness and satisfaction. One urban middle school implemented PLCs during the 2007-2008 school year. However, there had not been an investigation into the effectiveness of the PLCs. Using organizational learning theory, this concurrent mixed-methods study investigated the teachers' perceptions about PLC implementation and its influence on teachers' professional learning satisfaction. Quantitative data consisted of 52 participant responses from the "School Professional Staff as Learning Community Questionnaire" (SPSLCQ). Descriptive data analysis revealed only a low-level presence of the effectual PLC principles described in the literature. Qualitative data consisted of a typological analysis of eight teacher interviews, which revealed teachers' dissatisfaction with their PLC experiences. In conclusion, it was difficult to ascertain the influence PLCs had on teachers' professional learning satisfaction because the PLC implementation was not implemented as recommended in the literature. Other factors, such as hostile work environment and teacher isolation, may have also contributed to teachers' dissatisfaction. These findings reveal the need to conduct further research on the effectiveness of PLCs with schools that consistently implement PLC principles as described in the literature. This study contributes to social change because it demonstrates the need for district level and school site monitoring of PLC implementation and evaluation, which will ensure teachers' effectiveness and professional learning satisfaction in the PLC framework. [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.]