The oxidation and enhanced detection of cresols at a multi-wall carbon nanotube (MWNT) surface modified with an electrochemically deposited copper hydroxide film on the MWNT interface is reported. Copper nanoparticles were electrodeposited under potential control on the surface of MWCNT-modified screen-printed carbon paste (SPCP) electrode. Microscopy measurements (Field Emission Scanning Electron Microscopy) have provided details on the electrochemically controlled nucleation and growth mechanisms of Cu nanoparticles. In particular, Cu growth was found to be rapid and progressive within a time with an increasing nanoparticles density. Comparison of different modified electrodes shows that SPCP electrode modified with MWNT-copper and covered by Nafion offering the most favorable layer for constant-potential amperometric detection. The electrodeposition of copper onto the MWNT–Nafion layer led to an increasing of the analytical response (vs. that observed at the MWNT or screen printed electrodes alone). The results were also showed that MWNT-Cu composition promotes electrocatalytic process for oxidation of cresols.