Cytogenetic results on 234 spontaneous abortions showed 109 (46.6%) to have a chromosome abnormality. The results were analysed separately for the four major ethnic groups of which the population was composed and no differences in the proportion or types of chromosome abnormalities seen. The results of this survey were found to be very similar to other major published surveys and it therefore appears, on present evidence, that neither geographic location nor racial group affects the frequency of chromosome abnormalities seen among human spontaneous abortions. The sex ratio among the chromosomally normal and abnormal abortuses and the effect of parental and gestational age were discussed.