This study aimed to evaluate the influence of densities 8, 32, 56 and 80 fish/m3 on the productive performance of Pimelodus maculatus in 1m3 cages installed in 0.19ha earthen ponds without water renewal, located on private property in Santo Amaro da Imperatriz, Santa Catarina. Fish were fed daily with extruded commercial ration containing 32% of crude protein, in a proportion of 5.0% of the stocked biomass. Fish were sampled monthly (30% of the stocked fish) in each cage to evaluate length, weight, specific growth rate, survival, condition factor and biomass. Final length and weight were the same at densities 8, 32 and 56 fish/m3, with values higher than those registered with 80 fish/m3. The survival was the same at the different densities, with a mean of 91.4 ± 5.4%, whereas a higher biomass was registered with 56 and 80 fish/m3. The results showed that density influences fish growth and indicated 56 fish/m3 as the ideal for the performance of P. maculatus juveniles. However, additional information must be produced to optimize the species biomass production.