We have carried out an explicit closed-form determination of the inverse dielectric function for a single one-dimensional (1D) quantum wire embedded in a nonlocal 3D bulk semiconductor plasma and analyzed the coupled mode plasmon dispersion relation in the hydrodynamic model. Our analysis shows that the coupled 1D-3D plasmon is damped due to even small nonlocality of the 3D plasma. Also, there is a new nonlocal low frequency mode which does not exist for either the quantum wire or the nonlocal host in the absence of the other. (C) 2002 Elsevier Science Ltd. All rights reserved.