p-coumaric and ferulic acids are natural phenolic phytochemicals present in seeds and leaves usually in very low concentrations. For this reason, their detection and identification using traditional techniques of vibrational spectroscopy is problematic and requires the use of advanced methods to reduce the detection limit Both p-coumaric and ferulic acids are significant for their antioxidant properties and other biological activities such as antiallergic, hepatoprotective, anticarcinogenic or modulation of enzyme activity. Surface-enhanced Raman scattering (SERS) spectroscopy appears a good tool for their study and detection. In SERS spectroscopy, the mechanism of analytes adsorption on the surface of a plasmonic metal substrate plays a key role, since the formation of a surface complex and its geometry fundamentally influences the enhancement of spectral response. This work was aimed at in-situ SERS spectroelectrochemical study of p-coumaric and ferulic acid showing the dependence on applied potential and changes in adsorption mechanism. The SERS spectra were collected at 785 nm excitation wavelength on gold, silver and copper rough electrodes. The applied potential significantly influences the orientation of the molecules towards the active sites of the metal substrate and their overall spatial arrangement on the surface in terms of the individual adsorption mechanisms.