Population data across the nation demonstrates the growing number of students in public schools who are from culturally and linguistically diverse backgrounds, while public school data reflects a teacher population that is mainly white, middle class and female. While new teacher programs are beginning to respond to this diversity, in-service teachers may not have had much, if any, preparation to teach this growing population of students. Research has also shown that traditional models of one-shot or workshop-type staff development rarely have a lasting impact on in-service teachers as these types of models typically fail to take into account specific teaching contexts or teachers' individual traits, and are not consistent or long-term enough to enable teachers with time to practice and reflect on the new information. This multi-case study sought to identify the key components necessary in design, implementation and evaluation of an in-service staff development system specifically targeted at fostering teacher growth in knowledge, skills and dispositions to effectively teach culturally and linguistically diverse students. Key findings include the importance of differentiating staff development for each teacher, the critical impact context plays in the success of staff development efforts, the importance of providing tools for teacher reflection, and the influence of the principal on site- based staff development programs. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]