A surface vibrational study of a stearic acid/silver (Ag) flake system is reported. The chemical nature of this interfacial system was examined with surface enhanced Raman scattering (SERS) as a function of sample temperature. The SERS spectrum from the room temperature flake exhibited vibrational peaks that were attributed to a carboxylate species bound to the Ag substrate through the oxygen atoms in the terminal end group. The surface species remained stable to temperatures up to 150 °C, above which a partial decomposition to an amorphous carbon layer was observed. In addition to the Raman studies, an IR‐visible sum‐frequency (SFG) measurement from a stearic acid/smooth Ag substrate proved a useful probe of the C‐H stretches in the terminal methyl group of the molecule. The SFG signal from the asymmetric C‐H stretch in the methyl group exhibited a temperature dependence that was similar to the SERS response from the surface carboxylate group, namely, a marked and irreversible decrease in signal levels for temperatures above 150 °C.