Although twins constitute only about 2.4 per cent of total births in less developed countries, they account for about 12 per cent of neonatal deaths and about nine per cent of infant deaths. Twin mortality in less developed countries has almost never been analysed systematically. We examine survival among twins as contrasted with that among singleton births by using 2692 twin observations pooled from 26 standardized Demographic and Health Surveys. Weakened by gestational and other biological complications, twins seem to be more vulnerable to detrimental demographic and household socio-economic influences than singletons. Twinning tends to amplify, or at least retain, whatever group differences exist among singleton births.