Between February 20 and October 31, 2003, 2034 sows were inseminated with semen collected from 13 Hungarian Landrace boars. Altogether 16,013 piglets were born: 13,801 (86·2 per cent) alive, 796 (4·97 per cent) stillborn and 156 (0·97 per cent) mummified. A total of 1260 (7·87 per cent) of the pigs developed signs of postweaning multisystemic wasting syndrome (PMWS). In the groups of sows inseminated with semen from each of the 13 boars, the percentages of farrowings producing piglets with signs of PMWS, stillborn piglets or mummified piglets were very high (59·4 per cent, 57·6 per cent and 13·8 per cent, respectively). There were significant differences between the proportions of piglets with signs of PMWS, stillborn piglets and mummified piglets sired by the different boars: 3·06 to 15·6 per cent, 1·76 to 8·52 per cent and 0 to 3.22 per cent, respectively.