A proteolitic enzyme was purified from Bothrops brazili Peruvian snake venom using Sephadex G- 100 followed by CM-Sephadex C-50, In both two cases with 0.05M ammonium acetate pH 7,0. The enzyme was purified 3,2 fold with 52,5% of yield and by gel filtration the enzyme showed 18 000 of molecular weight, while the PAGE-SDS showed only on9 protein band of 22 000 in the presence of mercaptoethanol and 20 300 under nonreducing conditions which suggests that the enzyme has a single polypeptide chain with disulfide bond. The enzyme hydrolizes fibrinogen, fibrin, casein and afbucnin, but not hemoglobin. and mioglobin. The enzyme is a Aa-fibrinogenase because preferentially hydrolizes the Aa chain of the fibrinogen molecule. This activity is inhibited by EDTA hut not by PMSF, TLCK, iodoacstate and pepstatin, suggests that is a metalloproteinase, however the ions Ca+-+, Mg++ and Zn+f cannot reactivate the inhibition by EDTA. Finally the enzyme is stable up to 45 °C and in its effect on fibrin the enzyme is to attack a chain rapidly.