The modeling of slurry-phase reactors for petroleum hydrocracking has been reviewed and analyzed. A general description of the flow regime was proposed, and it is anticipated that due to the operating conditions usually implemented in hydrocracking of heavy oils, the homogeneous bubble flow is usually considered. It was also found in the literature that most of the models are only able to describe the liquid-phase behavior, omitting the dynamic behavior of the gas phase, the dispersion, and deactivation of catalysts, as well as coke formation. Computational fluid dynamics formulations are preferred despite the computational effort involved in the calculations. Also in the majority of those models, simple pseudocomponent kinetic rate expressions have been applied, without enough experimental information referring to kinetic parameters. Finally a generalized reactor model, which considers all mass and heat transfer phenomena, is proposed based on the literature, and details are provided to estimate all of the model parameters. For slurry-phase hydrocracking systems it becomes evident the lack of experimental information needed for validation and the necessity of exploring different types of models, as axial dispersion models under different bubble flow regimes as well as deep study of the transitory state.