The present study carried out a first approximation of the optimum stocking rate in guinea pigs grazing during the rainy season in the Peruvian highlands, using an associated perennial pasture composed of Lolium multiflorum, Lolium perenne, Dactylis glomerata, Trifolium pratense, Trifolium repens y Medicago sativa based on individual body weight gain and per area, feed intake, feed conversion, pasture yield, production costs and cost benefit ratio. In total, 132 15-day-old male G guinea pigs were used in a randomized complete block design with three 60-day fattening cycles as a block and four treatments corresponding to stocking rates of 400 (T1), 500 (T2), 600 (T3) and 700 (T4) guinea pigs/ha/year. It was used areas of 200 m2 of pasture where groups of 8, 10, 12 and 14 guinea pigs grazed in T1, T2, T3 and T4, respectively. The results showed that there was no effect of the stocking rate...