This data release includes electron 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Day Nui Con Voi metamorphic massif, Vietnam. Rock samples were collected by Meng-Wan Yeh, Michael J. Kunk and Robert P Wintsch in 2011. Mineral separates were prepared and aliquots of amphibole, muscovite, phlogopite, biotite, and potassium feldspar were analyzed by the 40Ar/39Ar method at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. The 40Ar/39Ar data constrain the timing of exhumation of rocks within the massif.