An electrolytic bath containing silver(I), cobalt(II) and different complexing agents to electrodeposit Co-Ag coatings over vitreous carbon and silicon/seed-layer substrates is proposed. In situ electrochemical characterization of thin deposits is performed by means of stripping (potentiodynamic or galvanostatic) methods. These techniques allow detecting the heterogeneous codeposition of cobalt and silver. Electrochemical ex situ methods (polarographic and voltammetric methods) are implemented to quantify the silver and cobalt percentage in the coatings. Optimal analytical parameters for voltammetric method are established.