Carbon monoxide (CO) is a major component in typical feed gases for solid oxide fuel cells (SOFC). This paper presents a combined modeling and experimental analysis of electrochemical CO oxidation on Ni/YSZ patterned model anodes. A computational model representing the coupled behavior of heterogeneous chemistry and electrochemistry in terms of elementary reactions is developed, which allows for a quantitative description of electrochemical impedance spectra and current�voltage behavior. Excellent agreement between model and experiment was achieved for the complete experimental data set, which covers a wide range of CO/CO2/N2 gas compositions (4.0 �� 102 Pa � pCO � 5.1 �� 104 Pa and 9.5 �� 102 Pa � pCO2 � 9.2 �� 104 Pa) and operating temperatures (973 K � T � 1073 K). In the framework of the presented model a direct mechanistic interpretation of the experimentally observed electrochemical characteristics is obtained.