The present invention relates to an improved delayed coking process. A coker feed, such as a vacuum resid, is treated with (i) a metal-containing agent and (ii) an oxidizing agent. The feed is treated with the oxidizing agent at an oxidizing temperature. The oxidized feed is then pre-heated to coking temperatures and conducted to a coking vessel for a coking time to allow volatiles to evolve and to produce a substantially free-flowing coke. A metals-containing composition is added to the feed at at least one of the following points in the process: prior to the heating of the feed to coking temperatures, during such heating, and/or after such heating.