Guava cultivation in the irrigated areas of the semi-arid northeast of Brazil is of great socio-economic importance. Above all, due to the limitation of quality water for irrigation in this region, it is necessary to study techniques that enable the use of saline water in the cultivation of the species. The aim of this study was to assess the tolerance of guava rootstocks to increased salinity in irrigation water, under fertilisation with different doses of nitrogen. The experiment was carried out in a greenhouse at the Centre for Agrifood Sciences and Technology of the Federal University of Campina Grande (CCTA/UFCG), located in the municipality of Pombal - PB. The experimental design was in randomised blocks, in a 5 x 4 factorial scheme, with the treatments referring to five levels of electrical conductivity of the irrigation water (ECa) of 0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1 in interaction with four nitrogen (N) doses: 70, 100, 130 and 160% of N of the recommended dose for guava seedlings. Four replicates were used, with two useful plants per experimental unit, where the Paluma guava genotype was evaluated.