Nanoscale noble metal particles have great potential as optical-limiting materials, whereas the size effect of silver nanoparticles on the optical limiting has been seldom reported before now. Silver nanoparticles with different sizes are synthesized by a seed growth method, and their optical-limiting properties to nanosecond laser at 532 nm are investigated. The results showed that, under the involved conditions, the silver nanoparticles with relatively small particle size behave better for optical limiting, and the nonlinear absorption accounts for the optical-limiting behavior.