Boraflex is a neutron absorber material and is currently used in about 75 storage pools around the world for the control of reactivity of LWR fuel in storage. In this work, the effects of gamma radiation on the physical properties of Boraflex including dimensions, weight, Shore A hardness, density and dynamic shear modulus were investigated. Specimens of Boraflex were irradiated in de-ionized water in a o 6 0 Co facility to an integrated dose of 1 10 1 0 rad. The experimental results provide the asymptotic values of dimension changes, saturation dose levels and a basis for inferring property changes on a micro-scale. Results presented here aid in identifying the in-service property changes of Boraflex and represent the most accurate data for this material yet available.