We present the 2-year experimental mixed-methods findings of a two-generation English as a second language (ESL) program. This program combines a high-dosage, child-oriented curriculum for parents with Head Start for children in addition to family-based supportive services. At baseline and after 2 years, 189 Latinx and Zomi immigrant parents completed surveys while children completed skill assessments. A subset of 67 parents participated in focus groups regarding their experiences. Treatment parents reported significantly higher English writing skills and self-esteem and significantly lower language brokering and material hardship. There were no significant differences in children's outcomes. Possible explanatory mechanisms across multiple contexts were identified in the qualitative data. Evidence is promising that a Two-Generation ESL Program improves some outcomes for parents.