The main motivation for co-firing coal with biomass is carbon dioxide emission reduction, while it can also lead to sulfur oxide reduction and suppress formation of nitric oxide from fuel nitrogen. Due to the fact that the coal is mainly used for power generation in its pulverized form, the emphasis in co-firing technologies is often given to co-combustion of pulverized biomass and coal. This facilitates the modeling approach to biomass combustion, since it may be considered in a way similar to the coal dust modeling. On the other hand, when compared to the pulverized coal, there are also significant differences. The differences correspond to the biomass composition depending on its origin, to mostly larger particle size, as well as to an irregular shape of biomass particles. The paper presents a review of modeling approaches and discusses recent progress in prediction of processes during biomass co-firing with pulverized coal. The main aim of the review is to facilitate the selection of submodels and methods to those dealing with the problems of modeling and simulation of practical biomass-coal co-firing systems. Future needs, goals and challenges in the field are presented as well.