This research was performed in order to determine the effect of planting density on the growth of Mugil cephalus "smooth" and Brycon atrocaudatus "cascafe" in multi-trophic culture; for which he had two ponds of 900 m2 and 600 m2 of area, developing the experimental design paired samples with two treatments without repetition: 1.8 fish / m2 (Pond 1) and 2.3 fish / m2 (Pond 2). The fish were fed balanced 28% protein in double time: 09 and 14 hours, with food indices ranged from 10% at the beginning to 2% of the biomass at the end. Biometric checks were made monthly sampling of 50 smooth and 25 cascafes each treatment and analysis of variance and Tukey test were performed to determine significant differences in growth. Growth was affected by planting density in reverse to the "smooth" best grown in lower total density of 1.8 fish / m2: 135.47 mm and 31.93 g and in favorable direction for the "cascafe" whose growth it was higher in the density of 2.3 fish / m2: 191.64 mm and 82.13 g. The highest yield production was presented in the total density of 2.3 fish / m2: 37.37 kg and 622.89 kg / ha. The best conversion factor and greater feed efficiency corresponded to the density of 2.3 fish / m2.