A process for simultaneously hydrocracking multiple feedstocks wherein a first feedstock is hydrotreated in a hydrotreating zone to produce a hydrotreating zone effluent which is separated to provide a first vaporous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. The second feedstock and the first vaporous hydrocarbonaceous stream are hydroprocessed in a hydroprocessing zone to produce a hydroprocessing zone effluent. A third feedstock and the first liquid hydrocarbonaceous stream are hydrocracked in a hydrocracking zone to produce a hydrocracking zone effluent. The hydrocracking zone effluent and the hydroprocessing zone effluent are separated to recover hydrocracked hydrocarbons.