Yield and fruit quality of Washington navel orange trees in response to spraying both calcium chloride and zinc sulphate at 0.5, 1 and 1.5% and potassium sulphate at 1, 2 and 3% were evaluated during two successive seasons, 2013 and 2014 at Abou–EL Matamier, Beheira Governorate, Egypt. The experiments were designed as randomized complete block design with five replications. Results showed that all treatments were very effective in improving yield as well as average fruit weight (g), average fruit volume (cm3), average fruit diameter (cm), average fruit length (cm), vitamin C and TSS (%) rather than control. Also, the used treatments led to significant decreases in the juice acidity percentage compared to the control treatment. The best results with regard to yield and fruit quality were significantly obtained due to spraying Washington navel orange trees with 2 and 3% potassium sulphate treatments.