Single crystals of 1,4-diiodobenzene support almost dispersionless hole transport with mobilities similar to 13 cm(2) V-1 s(-1) near room temperature. The mobility slowly increases with decreasing T and has little dependence on electric field. A simple model of hole transport represents the data well. Ab initio calculations (see figure) indicate that the large iodine constituents may play an important role in intermolecular hole transport.