Technical Abstract: Heritabilities and genetic correlations for prolificacy, growth and fleece traits were estimated from Columbia data collected from 1950 to 1998. Number of records ranged from 27,009 to 31,401, 23,903 to 24,741, 2,449 to 29,572 for prolificacy, growth and fleece traits. Direct heritability estimates from single trait animal model analyses using REML were .09 for number lambs born (NB), .06 for number lambs weaned (NW), .07 for litter weight at weaning (LW), .27 for birth weight (BW), .16 for 120 d weight (WW), .41 for fleece grade (FG), .53 for fleece weight (FW) and .55 for staple length (SL). Maternal heritability estimates were .25 for BW and .08 for WW. Estimates of genetic correlations among prolificacy traits were positive (.84 for NB-NW, .79 for NB-LW, .94 for NW-LW). Between BW and WW both the direct and maternal genetic correlations were positive (.56 for direct and .58 for maternal). FG was negatively correlated with both FW (-.47) and SL (-.70); FW was positively correlated with SL (.55). Estimates of genetic correlations were low between BW and the prolificacy traits (.10, .00, .11 for NB, NW, and LW) and moderate between WW and the prolificacy traits (.33, .24, .73 for NB, NW, and LW). Estimated genetic correlations were small between fleece characteristics and prolificacy traits: for FW (-.13, -.14, .08), for FG (.17, .04, .00) and for SL (-.05, -.20, -.05) with NB, NW and LW, respectively. Growth traits were positively correlated with FW (.21, .18 for BW and WW); negatively correlated with FG (-.04, -.11 for BW and WW) and SL was positively correlated with BW (.05) and negatively correlated with WW (-.04).