The spontaneous reduction of Ag+ ions in N,N-dimethylformamide (DMF) (in the absence of a protecting agent) leads to the homogeneous deposition of silver nanoparticles on clean glass surfaces in contact with the solution. The process of reduction and deposition can be performed at room temperature and in the dark, but the use of visible or UV radiation affects the reaction rate and the morphology of the deposited films. The deposition conditions can be tuned so that a homogeneous monolayer of silver nanoparticles is deposited on the whole surface.