SUMMARY:A study was made of selected properties of 189 psychrophilic bacteria isolated from chilled beef and associated sources. Of these, 182 were Gram‐negative and 7 were Gram‐positive. Of the former, 128 were typical pseudomonads with polar flagella. They were resistant to penicillin and oxidized glucose to acid. There were 52 non‐motile Gram‐negative bacteria of which 42 were judged to be pseudomonads on the basis of penicillin resistance and the oxidation of glucose to acid. Flagellar characters were associated with the production of green pigment, with the production of acid from lactose and with resistance to several anti