OBJECTIVE: To explore regional and ethnic differentials in under-five mortality in Mozambique in relation to other determinants.DESIGN: Retrospective follow-up study.SETTING: Mozambique.RESULTS: Compared to children of Xitsonga mother's, children of Emakua and Cisena mother's had a mortality risk of 1.47 (CI = 1.06-1.90) and 1.21 (CI = 1.00-1.62) respectively. The excess mortality risks were partly explained by demographic, household environment, socioeconomic factors including region of residence.CONCLUSION: Ethnic affiliation of the mother (measured by the first language the mother spoke) was statistically associated with under-five mortality in Mozambique. Children of mothers of Emakua and Cisena ethnic affiliations and living in the North and Central regions had the worst survival chances. The relation between mother's ethnicity and under-five mortality was largely explained by demographic, socioeconomic and environmental factors.