Hydrocarbons are converted by contacting them at hydrocarbon conversion conditions with an acidic multimetallic catalytic composite comprising a combination of catalytically effective amounts of a platinum group component, a zinc component, a cobalt component, and a halogen component with a porous carrier material. The platinum group, zinc, cobalt, and halogen components are present in the multimetallic catalyst in amounts respectively, calculated on an elemental basis, corresponding to about 0.01 to about 2 wt. % platinum group metal, about 0.01 to about 5 wt. % zinc, about 0.05 to about 5 wt. % cobalt, and about 0.1 to about 3.5 wt. % halogen. These metallic components are uniformly dispersed throughout the porous carrier material in carefully controlled oxidation states such that substantially all of the platinum group metal is present therein in the elemental metallic state, substantially all of the catalytically available cobalt component is present in the elemental metallic state or in a state which is reducible to the elemental metallic state under hydrocarbon conversion conditions, or in a mixture of these states, while substantially all of the zinc is preferably present therein in an oxidation state above that of the elemental metal.