The structure of Co-Mo/TiO2 nano-composite coatings electrodeposited for long-term periods (between 1.5 and 31 h) on pure cobalt is investigated by means of electrochemical measurements and field-emission scanning electron microscopy (FE-SEM) with an integrated electron dispersion spectrometer (EDS). From the obtained results, two stages are identified during electrodeposition. Microstructure and growth mechanisms associated to each stage are presented and discussed.