The objective of this study was to verify if the diet protein level affects the genesis of the repair tissue in rats submitted to a poly-chloro-vinyl (PVC) sponge implantation, as well as to analyse the possible alterations in the synthesis of the mucopolysaccharides acids (glucosaminoglycans) by the histophotometry technique. Forty five Wistar weanling male rats, at 21 days of age, were divided into three experimental groups; the groups were fed diets al 6%, 15% and 40% protein level from casein source, during at 69 days period. The animals which received the low protein diet (6%) presented an inhibition in the evolution and maturation of the granulation tissue mainly in the 4th, 7th and 10th days after the sponge PVC implantation. It was also observed that there was less infiltration of the inflammatory cells, less fibroblasts proliferation, reduction of the collagen fibers synthesis, neovascularization decreased and an inhibition of the mucopolysaccharide acids synthesis.42414-9