Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of five N-benzylamino(boronphenyl)-methylphosphonic acids: N-benzylamino-(3-boronphenyl)-S-methylphosphonic acid (m-PhS), N-benzylamino-(4-boronphenyl)-S-methylphosphonic acid (p-PhS), N-benzylamino-(2-boronphenyl)-R-methylphosphonic acid (o-PhR), N-benzylamino-(3-boronphenyl)-R-methyl-phosphonic acid (m-PhR), and N-benzylamino-(4-boronphenyl)-R-methylphosphonic acid (p-PhR) adsorbed on nanometer-sized colloidal particles (20–25nm). For example, we showed that all of these molecules interact with the colloidal surface through a boronophenyl ring, which plane remained vertical on the surface. For p-PhS, a preferential interaction between the PO bond and the colloidal silver surface is observed to be stronger than for the remaining compounds. The P(OH) 2 and B(OH) 2 fragments take part in the adsorption process. However, the BO bond of p-PhS and p-PhR seemed to be tilted with respect to the silver surface.