Aim Health literacy is a potential factor contributing to health disparities in migrant groups. This exploratory work sought to investigate the validity of the health literacy questionnaire (HLQ) in exploring the health literacy needs of migrant people in a vulnerable borough of Montpellier, France. Subjects and methods The multidimensional HLQ was administered, together with cognitive interviews, to 17 persons with varying French language skills benefiting from a community health education program. Results The great majority of HLQ items were understood as intended in this sample, with markedly heterogenous health literacy profiles. Participants with the lowest education found some words or concepts difficult to understand, but the endorsed response options were consistent with their narrative during qualitative interviews. Conclusion This study adds to the growing body of evidence ensuring the cross-cultural validity of the HLQ lying on culturally generic translated item concepts. This is of importance for the exploration of both health literacy strengths and weaknesses, which provides critical insights into potentially relevant responsiveness to the needs of vulnerable persons experiencing the complex challenges of migration.