The crosstalk between two biologically important signaling molecules, nitric oxide (NO) and hydrogen sulfide (H2S), proceeds via elusive mechanism(s). Herein we report the formation of H2S by the action of NO on synthetic [2Fe-2S] clusters when the reaction environment is capable of providing a formal H-center dot (e(-)/H+). Nitrosylation of (NEt4)(2)[Fe2S2(SPh)(4)] (1) in the presence of PhSH or (Bu3PhOH)-Bu-t results in the formation of (NEt4)[Fe(NO)(2)(SPh)(2)] (2) and H2S with the concomitant generation of PhSSPh or (Bu3PhO center dot)-Bu-t. The amount of H2S generated is dependent on the electronic environment of the [2Fe-2S] cluster as well as the type of H-center dot donor. Employment of clusters with electron-donating groups or H-center dot donors from thiols leads to a larger amount of H2S evolution. The 1/NO reaction in the presence of PhSH exhibits biphasic decay kinetics with no deuterium kinetic isotope effect upon PhSD substitution. However, the rates of decay increase significantly with the use of 4-MeO-PhSH or 4-Me-PhSH in place of PhSH. These results provide the first chemical evidence to suggest that [Fe-S] clusters are likely to be a site for the crosstalk between NO and H2S in biology.