Improving piglet survival has three reasons, including general success in selection for increased litter size; larger litters increase the necessity of fostering, and concern for animal welfare. Losses in litter size occur in the uterus, farrowing, and pre-weaning. The survivability depends on the piglet’s genes, the maternal genes, and the milking sows genes (if fostered). Simultaneous selection for litter size and birth weight will increase birth weight dramatically, but will not increase survival nor increase litter size. Eight years of selection for litter size and piglet survival can increase litter size and survivability. Almost all economically important traits can be improved genetically. Even for a trait with a very low heritability (such as piglet survival) genetic progress can still be made. Some work being done is on survival and birth weight, survival and fatness, survival and feed intake, and survival and mothering ability.