The objective of this research was to evaluate the optimum density in the rearing of guinea pigs of the Peru breed in the growth phase, under humid tropical conditions. We used 200 guinea pigs (100 males and 100 females) weaned from the Peru breed at 30 days of age, distributed in a DBCA with 5 treatments (density = 8, 9, 10, 11 and 12 animals/0.96m2) and 4 replications, being sex the blocking effect, the significant difference between treatments was performed with Duncan's test (5%), in addition, the linear regression test was performed to determine the optimum density. In the zootechnical parameters, significant differences were observed (P<0.05); obtaining for weight gain, feed consumption and feed conversion the best result was evidenced in treatment T5 (D12) with 9.05g, 54.11g, 6.03 respectively. It was concluded that the best density for raising guinea pigs of the Peru breed in ...