Supported iridium-containing hydrocarbon conversion catalysts which are at least partially deactivated due to the deposition of carbonaceous residues thereon during contact with hydrocarbons are regenerated by contacting the residue-containing catalyst, prior to contact with oxygen at elevated temperature, with a chlorine-containing reagent to increase the catalyst chlorine content to a level in the range of from about 0.7 to 2.0 wt. %, based on anhydrous, carbonaceous residue-free catalyst, and thereafter contacting the catalyst with a substantially sulfur-free gaseous mixture containing oxygen at a temperature varying from about 775.degree. to 900.degree. F. for a time sufficient to burn at least a portion of the carbonaceous residue from the catalyst while maintaining at least 0.7 wt. % chlorine on the catalyst during contact with said gaseous mixture.