A coker heavy gas oil (HGO) derived from Athabasca bitumen was hydrotreated over a typical Ni/Mo catalyst in a downflow fixed bed pilot-scale reactor in order to investigate HGO hydrotreating kinetics in a wide range of operating conditions and to provide feedstocks for evaluating the processibility of hydrotreated HGOs in fluid catalytic cracking (FCC) units. A microactivity test (MAT) reactor loaded with a typical commercial FCC catalyst was used for the latter purpose. Rates. of hydrodenitrogenation (HDN), 343 degrees C+ conversion to lighter materials (mild hydrocracking or MHC), and density reduction of HGO during hydrotreating are adequately described by modified first-order kinetics, while the rate of hydrodesulfurization (HDS) can be described by 1.5th-order kinetics. MAT experiments show that bitumen-derived coker HGO can make a premium FCC feedstock if it is hydrotreated under appropriate conditions.