Teachers today have a revolutionary role of introducing techniques to their students to enhance learning in traditional classroom settings. To accomplish this, teachers have to use blended learning strategies such as flipped classroom to enhance learning by blending online and face-to-face settings. However, to apply these strategies teachers have to be prepared and willing to integrate technology. This investigation aimed to determine how teachers' pedagogical, technological, and emotional readiness related to their acceptance and intention to use the flipped classroom methodology for ESL courses in Puerto Rico. Using a descriptive-correlational research design to collect and evaluate quantitative data, the investigator examined the relationship between teacher readiness factors and the determinants of technology acceptance and intention to use technology, in this case flipped learning. The participants of this study were English as second language teachers at the secondary school level (7th to 12th grade) from schools in Puerto Rico. I gathered data an online survey titled Survey of Teachers' Readiness, Acceptance and Use of Technology in Flipped Classrooms. This survey was a modified version of two existing surveys from The Unified Theory of Acceptance and Use of Technology survey (Venkatesh et al., 2003) and a survey on teacher readiness created by Al-Awidi and Aldhafeeri (2017). A total of 66 teachers from the Puerto Rico public school system answered the survey. The results of this study revealed a relationship between readiness constructs and the predictors of acceptance and intention to use technology, but results were inconclusive regarding the relationship between teacher's readiness and the specific intention to use flipped classroom. [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.]