Oleic acid-stabilized 100-angstrom-diameter silver particles have been spread at air-water interfaces in a Langmuir film balance. Surface pressure vs surface area isotherms, reflectivity measurements, and Brewster-angle and transmission electron microscopies demonstrated that increasing surface pressure resulted in the transition from gaseous and liquid phases of mixed oleic acid/silver particle domains to closely packed, well-separated monoparticulate silver domains which ultimately collapsed to multiparticulate layers. Sequential transfer to solid substrates by the Langmuir-Blodgett technique led to the formation of multiparticulate layers of silver clusters.