The present review covers the recent progresses on the development of predictive methods for the study of properties of pure ionic liquids over the past decades. After a review on several predictive methods of different kinds and used for different interesting properties, this review focus attention mainly on semi-classical-based Equations of State. The theoretical backgrounds of the Equations of State reviewed here comprise perturbed hard-sphere theory, Weeks-Chandler-Anderson perturbation theory, simplified perturbed hard-chain theory, statistical associating fluid theory, and electrolyte perturbation theory. The majority of them were established by some semi-theoretical methods, i.e., the theoretical or molecular schemes were coupled with the parameter estimations coming from the classical thermodynamics and empirical approaches. The performance and accuracy of these Equations of State for representing several thermophysical properties are surveyed here through the literature. Also, some comparisons were made between the predicted compressibility (density variation with pressure) and expansivity (density variation with temperature) curves for a typical ionic liquid obtained by using the semi-classical equations reviewed here and the previously reported Molecular Dynamics results given in the literature. The results revealed that Equations of State that used the adjustable molecular parameters could fit high-pressure compressibility curves from Molecular Dynamics calculations better than those used bulk scaling parameters. However, in the case of density-temperature curves there is not agreement between the results obtained from simulations in literature and Equations reviewed in this work. (C) 2018 Elsevier Ltd.