Nanosilver is widely used in medicine, industry, and other applications where it poses a high potential risk for human health, even though little information is available on its toxicity to vital organs. This study was conducted to determine the histopathological changes induced in renal tissues by various sizes of silver nanoparticles (SNPs). Male BALB/C mice were exposed to various sizes of SNPs for 5 weeks. Renal tissue samples from all members of all experimental groups were subjected to histological processing and histopathological examination. SNPs caused glomerular and tubular alterations in the form of tubular degeneration, necrosis, eosinophilia, glomerular shrinkage, and Bowman's capsule thickening. Moreover, SNPs induced interstitial intertubular regeneration, mononuclear inflammatory cell infiltration, proteinaceous casting, and fibrocyte proliferation. These results indicated that smaller particles (10 and 20 nm) were more toxic than the larger ones (40, 60, and 100 nm). In addition, the cortex was more affected than the medulla, and the proximal tubules were more affected than the distal ones. The results of the current investigation reveal that SNPs induce histomorphological alterations in renal tissues, with size being a key factor in the toxicity of these particles.