The focus of this article is on adult literacy in adult basic education (ABE) programs with special emphasis on English as a Second Language (ESL) students. The article intends to highlight several relevant points in ABE ESL literacy instruction. It focuses on (a) the nature of adult learning, (b) the structure of ABE programs, (c) who the students, in particular ESL students, are in ABE programs, and (d) ESL students' instructional needs. It also refers to the Generation 1.5 phenomenon and describes studies comparing native and nonnative English-speaking students' literacy development. Finally, it proposes some recommendations for future research projects and underlines the necessity of developing literacy programs with a focus on adult ESL learners.