Immigration has resulted in an increase in the number of English Language Learners present in schools across the United States. The language barrier and lack of teacher preparation for handling the learning differences of these students have resulted in low reading achievement levels in elementary schools, further promoting the chances that these students will eventually become high school drop-outs. The purpose of this study was to determine the effectiveness of the use of methodologies in a developmental bilingual program in increasing reading mastery levels in English for Spanish-speaking students in the primary grades. For the study, the researcher compared and analyzed a sampling of reading achievement data scores, issued teacher questionnaires, and conducted student interviews on students included in the developmental bilingual program at one school in North Carolina. These methods provided teacher perceptions of the effectiveness of the program, along with student reading mastery levels. The information obtained from the study was used to aid district leaders and directors of curriculum in a county in North Carolina determine if the program offered enough benefits to the student populations within the school district for it to be continued and expanded. [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.]