Mathematical models prove to be an useful tool to define the best water management in saline conditions. A review of the most known existing models is given in the paper. They can be divided into two main groups: seasonal models, based on an equation that relates yield to the amount of applied irrigation water of a given salinity; transient models, following a mechanistic approach, but generally simplistic in crop dynamics. A new crop-based model for water salinity management is proposed to rectify deficiencies in existing models with respect to crop response to salinity. The CERES-Maize model was modified in the original water uptake term for assessing salinity effects on crop. Reasonable agreement was found between model predictions and experimentally measured data for crop evapotranspiration, biomass, LAI and grain yield. The model may represent a valid tool for salinity risk evaluation.