A growing number of studies have reported the potential use of computer-assisted language learning (CALL) and other types of technology for ESL and EFL students. So far, most studies on CALL have focused on CALL-classroom comparisons (Chenoweth & Murday, 2003; Chenoweth, Ushida, & Murday, 2007; Fitze, 2006; Neri, Mich, Gerosa, & Giuliani, 2008), students' perceptions of and attitudes toward CALL (Lee, 2005; Lin, Winaitham, & Saitakham, 2008; Winke, Goertler, & Amuzie, 2010; Miyazoe & Anderson, 2010), and students' preparedness and training for CALL (Altun, 2004; Barrette, 2001; Winke & Goertler, 2008). Clearly, research already offers new insights based on students' own voices and experiences in CALL environments. However, little attention has been paid to the experiences and perceptions of teachers, especially those who are teaching adult English language learners (Bloch, 2004; Byrne, 2007; Chang, 2007; Chinnery, 2008; Hampel & Stickler, 2005; Marriott & Torres, 2009). Even though CALL applications can potentially energize ESL/EFL students, it is clear that, without technologically prepared teachers, the CALL environment might not be effective. This study explored ESL and EFL teachers' experiences and perceptions towards the use of CALL to teach adult English language learners, and how CALL could impact language teaching and learning. Furthermore, this study explored a number of factors affecting the ESL and EFL teachers' integration of CALL. For the qualitative data collection, sixteen participants (8 ESL & 8 EFL) were interviewed for approximately 40-60 minutes and asked to share their background information and to reflect on their perceptions about CALL in English teaching and learning. For the quantitative data collection, eighty participants (40 ESL & 40 EFL) took approximately 5-10 minutes to complete the study's survey (PCALLS). In the PCALLS, participants were asked to describe their background information and perceptions toward CALL. The procedure to analyze the data comprised two phases, corresponding to the three qualitative and three quantitative research questions. Data gleaned from in-depth interviews were analyzed utilizing the phenomenological approach to data analysis; data obtained from survey were analyzed using the SPSS 18.0 package for Mac. Overall findings indicated that the ESL and EFL teachers in this study held positive perceptions and attitudes toward the integration of CALL. However, technology was recognized as a momentous but supplementary tool and was used in a predominantly traditional way and a teacher-centered setting. Findings also suggested that the ESL and EFL teachers in CALL-integrated classrooms were more classroom facilitators and less information providers who developed students' ability to learn English independently. Hence, with respect to the roles of teachers, there is an inconsistency between the ESL and EFL teachers' beliefs and actual practices. With respect to learning from participation in CALL, students with any English proficiency level benefited, students enhanced their language skills, and students had ample opportunities to interact with authentic English language materials and native speakers of English. Furthermore, with respect to teaching, CALL promoted innovative teaching practices, increased English teaching effectiveness, and improved instructional approaches and strategies. Finally, teacher-, student- and instructional-related factors were related to effective use of CALL in classrooms. Practical implications for instructional practice and school policymakers and administrators included the creation of a "CALL Club," the creation of a "Mentoring Committee," the use of free resources available online, and the requirement of CALL-related training in preservice ESL/EFL teacher preparation 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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]