Cell suspensions of Listeria monocytogenes 5366, Staphylococcus aureus 976 and Pseudomonas aerugtnosa 110T were exposed to high pressure treatment from zoo to boo MPa for 5, 10 and 15 min at an initial temperature of 20°C in raw skimmed bovine milk, whey and phosphate buffer,PH 7.0 in order to determine their degree of inactivation.