Self-assembly of silver sulfide, Ag2S, nanoparticles is reported for different particles sizes. Monolayers of particles organized in a hexagonal network an formed over very large domains, Snail or large aggregates can also be produced. The observations indicate that the formation of self-assemblies of nanoparticles strongly depends on the preparation conditions of the samples, It is also shown that in the aggregates the particles are highly organized and form pseudocrystals with a face-centered cubic structure for various particles sizes.