A pot experiment was conducted at the Experimental Farm, Faculty of Agriculture, Assiut University, Assiut, during the summer seasons of 2014 and 2015 to study the effect of Silver Nanoparticles (SNP) on salt tolerance in tomato. The experimental soil type was clay. Split plot arrangement in Randomized Complete Blocks Design (RCBD) with four replicates was used. The salt solution (sodium chloride) concentrations [(0 %( control plots were irrigated with deionized water), 30, 60, 90, 120 mM/L)] were distributed in main plots, while the Silver Nanoparticles concentrations [(0 %( control plots were soaked in distilled water), 10, 20, 40 ppm)] were arranged in sub plots. The obtained results indicated that soaking tomato transplants in Silver nanoparticles for 24 hours had no significant effect on increasing tomato tolerance to sodium chloride salt within the used levels. This was reflected in negative effects on fruit number per plant, fruit diameter, average fruit weight, number of branches per plant and plant height. The control treatment (soaked in distilled water) of SNP was consistently superior for all studied traits. SNP treatments reduced the fruit number per plant, fruit diameter, average fruit weight, number of branches per plant and plant height