Immunophenotyping was carried out in the presentation bone marrow samples of 32 children with acute lymphoblastic leukaemia (ALL), living in the UAE. Twenty two had B-cell precursor ALL, 10 had T-cell precursor leukaemia. Clinical features were in accordance with internationally reported series. Analysis of ethnic origin showed that children of subcontinental origin (Indian and Pakistani) had a significantly higher proportion of T-cell ALL than their Arabic counterparts. This may reflect an interim phase in the pattern of ALL, between those of the developing and industrialized countries.