Results of 29 physiologic tests are reported for 1268 cultures of P. multocida from various hosts [birds, waterfowl, rabbit, seal, buffalo, bear, sea lions, squirrels, mink, muskrat and antelope] over a 10 yr period. Of the cultures, 97-100% fermented galactose, glucose, mannitol, mannose, fructose, and sucrose, produced H2S and indole, and reduced nitrate; 6-91% 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 97-100% of the cultures. Of 200 cultures tested for catalase and oxidase, all were positive. Apparently no test can determine the host from which the culture was isolated.