In this paper, the Eimeria oocyst output of two groups, pregnant ewes (group 1) and non-pregnant controls (group 2), which were followed from September 1993 to August 1994, is described. In both groups of animals the level of oocyst output was high during the minor rainy season. However, during the periparturient period the pregnant ewes showed the higher oocyst output. The oocyst output in both groups fell to similar levels after weaning of the lambs in March 1994. The species of Eimeria identified in order of dominance were Eimeria parva, E. pallida, E. faurei, E. ahsata, E. ovina, E. intricata, E. granulosa and E. ninakohlyakimovae. There were no differences in the species composition of oocysts in both groups of animals.