The photosensitized decomposition of ethane has been carried out at temperatures of 533, 553, and 573°K and over a pressure range from 3 to 40 Torr. The principal products were hydrogen, ethylene, butane and methane. A mechanism to account for the pressure and temperature dependence of the products is invoked which involves production of ethylene by unimolecular decomposition of ethyl radicals as well as by disproportionation of ethyl radicals. The formation of butane can be accounted for in terms of pressure dependent free radical recombination Hydrogen is assumed to arise by H atom abstraction from reactant. Methane formation is shown to involve secondary processes. These results agree as to major products but differ in minor products from earlier work on the Cd photosensitized decomposition of ethane and also from the high temperature mercury photosensitized decomposition.