We investigate the cosmic ray radial diffusion coefficient resulting from linearly polarized Alfv¿n waves propagating outward through an azimuthally structured solar wind. The analysis utilizes a diffusion coefficient derived from quasi-linear Fokker-Planck theory and a model solar wind stream in which the solar wind velocity varies linearly with azimuth. It is found that beyond 1 AU the stream significantly reduces the diffusion coefficient below that for a spherically symmetric solar wind. The diffusion coefficient is also found to reach a minumum value at a heliucentric distance of approximately 75 Rs, and this minimum moves outward with increasing steepness of the wave spectrum. The diffusion coefficient is a separable function of radius and rigidity below approximately 0.5 GV, but at higher rigidities it is found that the separability fails. Finally, it is concluded that the present diffusion theory is consistent with a cosmic ray gradient which decreases slowly with r and has a mean value, between 1 and 5 AU , of about 3%/AU for 1-GeV galactic protons.