Public school teachers must meet the unique needs of English language learners (ELLs) in the general education classroom. There is a need to understand teacher attitudes toward ELLs because attitudes can explain and influence teacher behavior and professional practice. The purpose of this quantitative study was to examine the relationships between attitudes and behavior with years of experience as well as professional development among teachers working with ELLs. Sociocultural, situational learning, and second language acquisition theories provided the theoretical foundation for the study. Data were collected from 286 teachers using the Teacher Attitudes Toward English-as-a-Second-Language Survey. Analyses included descriptive statistics, correlational analysis, independent sample t tests, and Mann-Whitney "U" test. Results indicated a significant, direct correlation between teachers' years of experience and their attitudes regarding coursework modifications. The independent sample t tests indicated significant differences in a subscale of the variable teaching behavior between participants who had and had not received adequate training. In addition, significant differences in teachers' attitudes existed among those teachers between participants who had and had not received professional development. The study can effect social change at the local site by fostering an increased understanding of how experience and professional development influences teachers' attitudes toward inclusion and behaviors toward ELLs, thereby highlighting the importance of professional development and experience for meeting the needs of ELL students. [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.]