Studies on the Cattle Egret were carried out in a heronry (80 m x 10 m) in a pure grassveld with extensive stockfarming in the Free State, South Africa. Mean clutch size (3.0, n = 1217) was found to be higher than in other places in Africa. Although hatching success was high (90%, 2.9 hatchlings per nest), reproductive success was low (37%, 1.1 fledglings per nest with eggs). The main reason for this seems to be human disturbance, aggressive interactions among breeding birds, tick infestation and adverse weather conditions. Breeding activities were more advanced in the highest (above 4 m) strata of trees and shrubs. Mean clutch size and hatching success in relation to nest location did not differ significantly, however fledging success tended to be higher in the colony centre.