The purpose of this study was to determine whether motivation to read, Spanish reading proficiency or English reading proficiency could predict the reading achievement scores of Hispanic emerging bilingual students. In addition, the researcher explored how the sociocultural context of the bilingual classroom influences students' reading motivation and reading proficiency in both languages. There were 171 fourth and fifth grade bilingual students who participated in this study. While it was determined that Spanish reading proficiency (I-Station Lectura Avanzada) predicted reading achievement on the Spanish State of Texas Assessment of Academic Readiness (STAAR) reading assessment scores and English reading proficiency (I-Station Advanced Reading) predicted English STAAR reading assessment scores, reading motivation as measured by the MRQ did not predict reading achievement scores on either STAAR test. Furthermore, one-on-one interviews with three fourth grade bilingual students and their respective Language Arts teachers revealed that there were several external factors which influenced the sociocultural context of the bilingual classroom. Based on Guthrie and Klauda's engagement model, it was inferred that these factors could either negatively or positively influence the development of students' reading motivation and proficiency in both languages. The following conclusions were drawn from triangulation of the data: bilingual teachers and their students valued reading in general and bilingual students valued reading in the language their teachers valued. In their role as Mama Gallina, bilingual teachers believed they were acting in the best interests of their students, but their instructional decisions were heavily influenced by their personal experiences. In addition, bilingual teachers showed varying degrees of nepantlera in their role as Mama Gallina. Additional studies are needed to examine bilingual classrooms which represent culturally responsive environments and how bilingual teachers develop their bilingual students' reading motivation and reading proficiency in both languages. The results from this study can contribute to literacy implications and future research recommendations. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]