By 2020, demand of maize in the developing countries will probably surpass the demand for both wheat and rice. Under rainfed conditions, lack of rainfall leads to an important yield decrement. To avoid this, the practice of supplemental irrigation is a promoting alternative. Nevertheless, as we can't allocate more freshwater for the agricultural sector, the only source of water for such practice could be the non-conventional one. An experiment was conducted in a greenhouse of the Mediterranean Agronomic Institute of Bari (Italy) in order to evaluate the impact of saline water use as supplemental irrigation. Under rainfed conditions, no-yield was registered; when supplemental irrigation was practiced, maize productivity was improved considerably: 2.33 t/ha, 3.13 t/ha and 4.43t/ha when irrigated with a water of 9 dS/m, 6 dS/m and 3 dS/m respectively. At the same time, freshwater application was reduced to 39% (from 172 to 74 l/pot).