Fresh venom was obtained by milking both sexes of adult Bothrops atrox snakes. Four biological activities were studied in both fresh and freeze dried venom: local hemorrhagic in guinea pig skin, proteolytic upon casein (caseinolytic), esterasic upon TAME and fibrinogen clotting activity. All activities were detected in fresh venom: Hemorrhagic (DHM = 0.93, DHR = 9.75 micrograms protein), caseinolytic (0.25 U kunitz/mg protein), esterasic (0.70 U/mg protein) and clotting activity (75.7 U NIH/mg protein). After freeze drying, all the biological activity of B. atrox venom enzymes decreased: hemorrhagic, caseinolytic and clotting activity in 50% and the esterasic activity only in 15%. Our results show that lyophylization decreases several important biological activities in snake venom related to a decrease in the venom enzymatic activities.