Multiple, simultaneous stressors in the family context during early childhood may compromise healthy adjustment to school, with potential long-term implications. Moreover, stressors across multiple contexts (e.g., home and school) can exacerbate the negative influences of stress on children's functioning. We investigated associations between parent-reported accumulated burden of family stressors and standardized early literacy and math scores, teacher-reported classroom participation, and child-reported school liking among 175 kindergartners. We also examined whether teacher-child conflict (i.e., a classroom stressor) exacerbated associations. Cumulative family stressors were negatively associated with children's early literacy, early math, and classroom participation, but were unrelated to school liking. High levels of teacher-child conflict worsened these associations for literacy (significantly) and classroom participation (at trend level). The combination of both high levels of cumulative family stressors and a highly conflictual relationship with teachers was negatively associated with school liking. No interaction was detected for math. Results highlight the role of family stress for school adjustment and address implications of conflictual teacher-child relationships for vulnerable children at the transition to formal schooling.