In a study of 1,141 consecutive deliveries at delivery centres in the Yemen Arab Republic, the effects of khat (catha edulis) upon the offspring have been studied. The leaves of the shrub khat contain euphorizing compounds and are chewed often, even daily, by many inhabitants. Non-users of khat (n = 427) had significantly fewer low birth-weight babies (less than 2,500 gram) compared to occasional users (n = 223) and regular users (n = 391). The khat-chewing mother was older, of greater parity and had more surviving children than the non-chewers. Significantly more khat-chewers had concomitant diseases. There was no difference in rates of stillbirth or congenital malformations.