Copper(I) bromide reacts under atmospheric conditions with tribenzylphdsphine; PBz3, in acetonitrile according to the following reaction scheme : 2CuBr + 2PB(z3) --> [CU(PBZ3)(2)][CUBr2]. The product, identified by spectroscopic techniques and X-ray diffraction, is the first known example of an ionic copper(I) compound with a tertiary phosphine which possesses a linear CuP2 coordination environment.