Electrochemical generation of free nitric oxide (NO) from nitrite (NO2-) catalyzed by iron meso-tetrakis(4-N-methylpyridiniumyl)porphyrin, [Fe-III(TMPyP)](5+), has been developed in this study. To obtain free NO, a cathodic electrolysis and an anodic electrolysis were performed in two connected flow electrolytic cells in sequence. The flow electrolytic cell upstream was used for cathodic electrolysis, where the solution of [Fe-III(TMPyP)](5+) and NO2- was reduced at -0.25 V (vs Ag/AgCl) into [Fe-II(NO2-)(2)(TMPyP)](2+) and [Fe-II(NO)(TMPyP)](5+) in sequence. The flow. electrolytic cell downstream was utilized for anodic electrolysis, where [Fe-II(NO)(TMPyP)](4+) formed from the upstream cell was oxidized at +0.40 V (vs Ag/AgCl) into [Fe-III(TMPyP)](5+) and free NO. Finally, NO was bubbled out from anodic electrolyte by argon gas. The mechanism and the optimum conditions for electrochemical generation of NO from NO2- catalyzed by [Fe-III(TMPyP)](5+) were studied in detail by voltammetric and spectroelectrochemical methods.