In the Brazilian semi-arid region, the occurrence of water sources with high levels of salts is a limiting factor for irrigated agriculture, requiring the use of salt stress-tolerant genotypes and fertilization strategies that enable their production. In this context, the objective was to evaluate the morphophysiology and quality of early dwarf cashew seedlings cultivated under irrigation water salinity levels and combinations of nitrogen and potassium fertilization. The experiment was conducted in a randomized block design, in a 2 x 4 x 3 factorial scheme, referring to two cashew genotypes (Faga 11 and CCP 76), four levels of electrical conductivity of irrigation water - ECw (0.3; 1.8; 3.3 and 4.8 dS m(-1)), and three combinations of nitrogen and potassium fertilizers (100:50; 50:100 and 100:100% of the recommended dose), with three replicates and two plants per plot. Relative water content, electrolyte leakage, number of leaves, leaf area, plant height, stem diameter, biomass accumulation and Dickson quality index were evaluated. Irrigation water salinity above 0.3 dS m(-1 )increased foliar electrolyte leakage and reduced seedling growth and quality index. CCP 76 stood out for presenting higher seedling quality under saline stress. The 50:100% combination of nitrogen and potassium fertilization in the Faga 11 genotype resulted in the lowest phytomass accumulation. Combined fertilization with 100:100% nitrogen-potassium provides the lowest foliar electrolyte leakage.