The aim of the study was to estimate genetic correlations between litter size in gilts and sows for number of born and number of liveborn piglets. Total 24 334 litters of Swedish Landrace (SL), Large White (LW), and both F1 sows; line 12 (SL P LW) and line 21 (LW P SL) were included. High genetic correlations for number of born piglets (0.92) and also for number of liveborn piglets (0.92) were obtained by animal model. Due to high genetic correlations litter size across litters from 1st to 6th parity can be treated as the same trait. The estimates of heritability for litter size in gilts and sows were higher for number of born (0.14) than for number of liveborn piglets (0.12). The results confirmed the adequacy of a simple repeatability model in the selection for litter size in the population analyzed.