The mid-Cretaceous Perubar VMS deposit, Central Peru, affected by contact metamorphism, has been the subject of a sulfur isotope investigation. The measured δ34S values for sulfate-sulfide pairs from the deposit indicate that close to equilibrium isotopic reequilibration occurred during metamorphism. After “filtering” the contact metamorphism effect, sulfur isotope desiquilibrium trends for coexisting sulfate-sulfide pairs were obtained on the δ34S versus Δ34S diagram, indicating a mixing between seawater sulfate and hydrothermal H2S. It suggests that contact metamorphism occurred in a closed system and that the original bulk sulfur isotope composition of the Perubar deposit was mostly preserved. Sulfur reequilibrated only locally, by isotope exchanges between adjacent sulfate and sulfide minerals.