Recent literature, mainly post 1990, on the fundamental processes and mechanisms of coal gasification is reviewed. Six main sections cover fundamental reactions, pyrolysis, high temperature gasification, gasification catalysts, and pollutant formation. The section on fundamental reactions reviews the mechanisms and intrinsic kinetics of the fundamental gasification reactions, and the various mechanistic and kinetic models suggested. The section of pyrolysis covers the physical and chemical mechanisms, modeling, weight loss behavior, volatile products, and char. High temperature gasification is reviewed in terms of char reactivity and parameters such as particle temperature, partial and total pressure, gasifying atmosphere, coal rank, surface area, and porosity. Furthermore, the structural models for char gasification are reviewed in this section. The section on gasification catalysts reviews the inherent catalysts for oxidative gasification and their influence on coal reactivity. Recent developments in the behavior of sulphur, nitrogen, and trace elements during gasification are reviewed in the last main section. It is concluded that whilst better understanding of the process of gasification may lead to development of empirical models for specific sets of conditions, the sheer complexity of the process makes it unlikely that there can be a fundamental, universal model of all coal gasification processes. Directions for further research are identified.