This paper describes the use of kinetic and reactor modeling to simulate the behavior of a commercial semi-regenerative reforming unit when two feedstocks (with and without benzene precursors) are employed, The feed without benzene precursors was prepared by fractionation of a typical reforming feed. A cut point of 88 degreesC was selected because most of the C-5-C-6 light naphtha is excluded. This cut point was not deep enough to remove the main benzene precurson cyclohexane. but other precursors, i.e. methylcyclopentane and n-hexane, were almost totally eliminated. It was decided not to increase this cut point value beyond 88 degreesC because this would reduce the flowrate of the feedstock to the reforming unit, which is not convenient due to refineries gasoline production policies. It has been shown that naphtha fractionation is a very good method for reducing the content of benzene precursors in reforming feedstocks. and consequently an important decrease in reformate benzene concentration can be achieved.