A retrospective study of 50 children newly diagnosed with acute lymphoblastic leukaemia (ALL) from December 1988 to November 1993 was carried out, examining the disease conditions and cytogenetic abnormalities. Of the 50 children, 8 had no cytogenetic examination of the marrow at the time of diagnosis and 7 had a poor yield from the marrow. Fifty percent of the remaining children had a normal karyotype. The rest of the children had hyperdiploidy and structural chromosomal abnormalities (mainly translocation and deletions) in equal proportions. Overall mortality of the whole group was about 26% with 2 lost to follow-up. There were 2 patients who relapsed while on treatment of whom 1 died. Cytogenetic abnormalities were correlated with clinical variables known to have prognostic significance. The group with hyperdiploidy had a significantly lower mean total white count at presentation and none of them died. The group with translocation abnormalities had a lower mean platelet count at presentation. Almost all in the group with hyperdiploidy and a great majority of the other 2 groups with normal or structural cytogenetic abnormalities were of B cell lineage. The median survival times for the hyperdiploid, normal karyotype and translocation patients were 1800 days, 1450 days and 700 days respectively.