Background. The tomato is the most important horticultural crop in the world, regarding area of cultivation and yield. The main production areas have arid and semi-arid climates, with scarce rainfall, which forces the use of saline water for irrigation - leading to a decrease in the agronomic yield of the crop. Currently, many soilless cultivation systems are considered for tomato production, although the behavior of the plants when saline water is used for irrigation is not known in detail. Methods. In this work we study the agronomic and physiological responses of the tomato variety ‘Óptima’, using different soilless crop systems (perlite substrate, hydroponics, and the nutrient film technique) and several levels of salinity in the irrigation water. The yield, quality parameters, vegetative growth, mineral composition, water relations, and gas exchange parameters were measured. Results and conclusions. Salinity caused changes in the water status of the plants, toxicity due to Cl- and Na+, and nutritional imbalances that altered the physiology of the plants, thereby reducing yield, although the fruit quality was improved. Regarding the crop system, hydroponics gave a higher marketable yield, both with and without salinity, with a consumption of nutrient solution intermediate between that of the nutrient film and perlite. Salinity reduced yield similarly in all systems. Plants cultivated with the nutrient film technique had the highest concentrations of Cl- and Na+ and the highest Na+/K+ ratio. The concentrations of Cl- and Na+ in the plants were not related directly to the yield loss. Therefore, the combined influence of the toxicity, osmotic effect, and nutritional imbalance seems to have been responsible for the yield loss.