A study was carried out to determine the effect of two genetic qualities of 'tilapia nilôtica' (Oreochromis niloticus), one local and another introduced, on the production of larva during 45 days of cycle. The investigation was conducted in the 'UnidadAcuicola Higuey' in the province of La Altagracia from October to November 2005. A completely randomized design was used, with two treatments: Tl = local tilapia, and Tll = introduced tilapia, with five and six repetitions, respectively. The experimental units were eleven ponds of 375 m2. A sexual proportion of 1.5:1 was used (females: male) for a density of sows of 0.5 ej /m2 and an average weight of 61 and 60 g, respectively. The variable measured was the production of larva. There were significant differences among the treatments. For the dependable variable total production, treatment II (mean = 160,283) significantly outyielded (prob>t = 0.0036) treatment I (mean = 132,687), value t = -3.91. We conclude that the introduced tilapia significantly outperformed the local tilapia; for each larva of local tilapia, 1.5 of the introduced tilapia was produced. For the reproduction/adaptation trait we denominated the populations as follows: good genetic quality for the introduced tilapia and bad genetic quality for the local tilapia.