The Cl and CIO quantum yields from the photodissociation Of Cl2O have been measured at 320, 360, 400, and 440 nm with the use of chemical ionization mass spectrometry (CIMS). All yields were measured at a pressure of 50 Torr and were normalized to a unit quantum yield at 255 nm. There is no evidence that either the Cl or ClO quantum yields deviate significantly from unity over the range of wavelengths employed. Comparison with other recent work on Cl2O photolysis is made, and implications with respect to the understanding of the dissociation dynamics involved are discussed.