The water retention curve (WRC) is often used to define the relative hydraulic conductivity, kr, of unsaturated soils. In this paper, the authors propose the use of the modified Kovács (MK) model, developed to predict the WRC using basic geotechnical properties, combined with some existing statistical models to estimate the kr function. The proposed equations are implemented in MATLAB®. After a preliminary validation based on comparisons with existing solutions, predictive results are presented for granular soils. These indicate a relatively good agreement with experimental results from drainage tests taken from the literature. A discussion follows on the advantages and limitations of the proposed approach.Key words: water retention curve, unsaturated hydraulic conductivity, predictive models, granular soils.