Approximately 4,000 children took part in a study of the reading attainments of children from different social-class backgrounds in Irish primary schools to find out if the progessive reading gap between children from different home backgrounds that has been observed in other countries could also be found in Irish school children. Tests were administered to every child in selected schools at four grade levels at yearly intervals from 1973 to 1977. The results indicated that for each grade at each time of testing the rank order of mean reading scores was always the same: group one, the children of professionals, white collar workers, and owners of large farms, consistently earned the highest mean score. Next, came group two, the children of skilled workers. Children of unskilled workers, owners of small farms, and the unemployed were always in third place. Some evidence existed for a progressively widening reading gap between social class groups in Ireland, although the effects were not large. (MKM)