Results of 29 physiologic tests are reported for 1,268 cultures of Pasteurella multocida from various hosts over a 10-year period. Of the cultures, 97 to 100% fermented galactose, glucose, mannitol, mannose, fructose, and sucrose, produced hydrogen sulfide and indole, and reduced nitrate; 6 to 91% fermented arabinose, glycerol, sorbitol, trehalose and xylose. Fermentation of dextrin, dulcitol, inositol, inulin, lactose, maltose, raffinose, rhamnose, and salicin, growth on MacConkey agar, change of litmus milk, production of urease and hemolysin, liquefaction of gelatin and motility were negative with 97 to 100% of the cultures. Of 200 cultures tested for catalase and oxidase, all were positive. Results of this study indicate that none of these tests will determine the host from which the culture was isolated.