A review of the experiments carried out by PETROBRAS at its Research and Development Center in the upgrading of the Irati shale oil obtained by the Petrosix Process is presented. For budget conveniences the Oil Shale Commercial Plant will be built in two stages. The first one will produce 25 O00 BPD of crude shale oil to be fed to a topping plant that delivers alight naphtha (10 vol%)-which is a good grade cracked naphtha after stabilization in a FCC unit-and a topped shale oil (90 vol%), which can also be normally processed in a FCC unit-without previous treatment-in the ratio SO/SO wt% with the usual gasoil feed. This'non conventional' shale oil refining route utilizes available process capacity of a PETROBRAS refinery, which is quite convenient when looking for minimizing investments. Whole shale oil hydrotreating or coking/hydrotreating are alternatives for the second stage of the Oil Shale Plant in which 50 O00 BPD of shale oil will be produced. In both cases, under mild operating conditions, the hydrotreated product doesn't require further refining, consisting mainly of a diesel, and minor amounts of a clear, stable naphtha, and an excellent FCC feed.