This study examined the extent to which English as a Foreign Language (EFL) high-school students believed mobile devices increase learning and learner satisfaction in the Thai school/classroom context, and whether they are prepared for autonomous learning using these devices. The participants were 277 students in eight high-schools in Southern Thailand who completed a questionnaire constructed around the core competencies of 21 st and autonomous traits in relation to mobile device use. The findings indicated that students had access/ability to use mobile devices, and either agreed/strongly agreed that mobile devices increase their learning potential and satisfaction, suggesting they are ready for autonomous learning using mobile devices in partnership with their 21st century learning skills. Recommendations are made for teachers and policy-makers to allow students to complement their learning using mobile devices.