Comparative production performances of Genetically Improved Farmed Tilapia (GIFT) and existing Nile, Oreochromis niloticus L. strains were assessed in five test environments (nursery systems, cisterns, hapas, net cages, and grow-out ponds) and six multi-locational sites (Trishal, Chandina, Manikganj, Paikgacha, Jessore Sadar, and Mithapukur) under on-station and on-farm conditions in Bangladesh. The mean weight gains at harvest of the GIFT strain was significantly higher (40-57%) than the existing Nile tilapia strain in all the trials.