In order to evaluated the impact of the high salinity reject brine from reverse osmosis desalina-tion on hydroponics lettuce cultivated in greenhouse an investigation was carried out in Mossoro, Northeast of
Brazil (5º11’S, 37º20’O and 18m above sea). Two lettuce cultivars (‘Verônica’ and ‘Babá de verão’) were cul-tivated with a basic nutrient solution with 1.1 dS m
-1
(control) during the crop cycle (1-28 days after transplant-ing – DAT) – T0and with basic nutrient solution containing 50% ofthe reject water from desalinization with
4.8 dS m
-1
exposed during 1-7, 21-28, 7-14 e 1-28 DAT (T
1, T2, T
3 and T
4, respectively). The addition of 50%
of brine reject from desalination into the hydroponic nutrient solution allows grow only ‘Verônica’ lettuce with
no reduction in fresh biomass. This lettuce cultivar shows to be more tolerant to salinity for all exposure time
with reject brine in the nutrition solution, despite the fact that ‘Babá de Verão’ cultivar is more productive.