To understand the relationship between water permeability and the pore structure of cementitious materials, this paper reviews the literature on both water permeability and pore structure and the correlation between them. Although the majority of this data is for cement paste, mortar, concrete and cemented soil are also included. Based on this study, it is established that the determination coefficient between water permeability and the total pore volume is very low. while those between water permeability and the critical threshold and median pore diameters, respectively, are moderate. On the other hand, the threshold pore diameter, derived based on percolation theory, exhibits a very high determination coefficient. The calculated water permeability, using the Katz–Thompson equation, agrees with the reported water permeability quantitatively to a certain degree, but is overestimated.