Abstract Time-of-flight secondary ion mass spectrometry (TOF-SIMS) in combination with ion imaging (lateral resolution 1 μm) has been applied to the analysis and characterization of Langmuir-Blodgett (LB) films. Silver, evaporated onto polycarbonate slices, was used as substrate material. Whereas films made from monomeric amphiphiles show defect structures of a diameter less than 1 μm, polymeric amphiphiles were found to form closed and homogeneous layers. Binary mixtures consisting of monomeric species in a polymeric matrix show a vertical diffusion of the monomeric component towards the surface. An additional application of imaging TOF-SIMS is demonstrated by the localization of contaminants.