The effect of plant growth regulators on barley powdery mildew caused by Blumeria graminis f.sp. hordei, under the influence of salinity, was conducted on two cultivars (Giza 123 and 126) in sand culture experiment. Plants were treated either by 10 ppm abscisic acid (ABA) or 25 and 50 ppm paclobutrazol (PBZ) as foliar spray, 3 weeks after sowing. Four levels of NaCl, i.e. 0, 50, 100, and 200 mM, were applied as soil treatment two days after spraying plant growth regulators. Disease severity and area under disease progress curve (AUDPC) were estimated on the leaves, at different intervals, during the experiment. Obtained data demonstrated that NaCl led to suppression of powdery mildew disease and had a harmful effect on plant growth parameters. Disease severity and AUDPC values were found to be higher in untreated control than in case of treatment by NaCl, plant growth regulators and their combinations. Treatments with PBZ and ABA significantly reduced powdery mildew severity on both cultivars and improved plant growth parameters (plant height, fresh and dry weight as well as grains yield) with increasing total chlorophyll content compared to the untreated control.