In this study, the heritabilities for weight and length at different ages, in gilthead seabream from the industry, were estimated. A sample of 300 offspring from 15 sires and 22 dams were analyzed. The genealogy was inferred using six microsatellite markers, five specific of gilthead seabream (Sparus auratus L.) (SaGT41a, SaGT41b, SaGT31, SaGT32, SaGT26) and one unspecific from Pagellus bogaraveo (PbMS2). An animal model was applied on data base using as fixed factors tank and culture system (intensive or mesocosms). The estimates of heritabilities were 0.25±0.08, 0.29±0.09, 0.29±0.09, 0.20±0.08, for weight at days 132, 167, 331 and 483 respectively. Also for these ages, the estimates of heritabilities for length were 0.36±0.09, 0.37±0.10, 0.21±0.08, 0.21±0.09 respectively.