In response to the research priorities of members of TESOL (Teachers of English to Speakers of Other Languages), this study investigated language learners' realworld tasks in mobile-assisted language learning (MALL) to inform the future development of pedagogic tasks for academic English as a second language (ESL) courses. The data included initial semistructured interviews with four ESL teachers and four college ESL students followed by an online task-based needs analysis conducted with 23 ESL teachers and 76 college ESL students at a university in the midwestern United States. Through the interviews and surveys, we identified how teachers and students used mobile devices and how they felt mobile devices could be used in language learning, and we categorized their target tasks in MALL according to the four language skills (reading, listening, speaking, and writing). The study found that ESL learners already use various mobile device functions, but that ESL instructors were less inclined to use these for teaching, suggesting that teachers may need further support and ideas before they can help their learners take advantage of their mobile devices for language learning. Both learners and teachers gave high rankings to tasks for listening and speaking as well as to activities integrated with SMS and the Internet. Based on the identified tasks, we created a MALL task typology to provide an initial authentic and sound resource for the future development of MALL tasks, lesson plans, and curricula.