This study explores the potential of native language literacy instruction for adult immigrant English language learners who have limited formal schooling or have had interruptions in their formal education. By examining 3 programs that provide native language literacy in combination with English as a second language (ESL) instruction, this study uncovers factors that affect students' participation and progress. Little educational research has been conducted on the growing population of immigrant adults in the United States with limited formal education in their native language. Public funding guidelines have drastically reduced programs' abilities to incorporate native languages into ESL instruction for adults, underscoring the need for research on best practices. In this interdisciplinary study, practitioners and students in Spanish language adult basic education and ESL literacy settings explore the motivations for Spanish-speaking immigrant adult learners to attend an adult basic education program in Spanish; factors affecting the persistence of this student sub-population; and programmatic elements key in impacting progress, attendance, and persistence of this sub-population. Findings including student participation data, themes emerging from interviews and focus groups, and programmatic elements are presented alongside implications for further research, policy, and practice. (Contains 3 figures and 5 footnotes.)