Mn-doped GaN nanowires have been prepared by reacting a mixture of acetylacetonates with NH3 at 950 degreesC in the presence of multi-walled (MWNTs) and single-walled (SWNTs) carbon nanotubes, the nanowires prepared with SWNTs being considerably smaller in diameter. GaMnN nanowires with 1%, 3% and 5% Mn so obtained have been characterized by X-ray diffraction, EDAX analysis and photoluminescence (PL) spectra. The GaMnN nanowires are all ferromagnetic even at 300 K, exhibiting magnetic hysteresis. The PL spectra of the GaMnN nanowires prepared with SWNTs show a large blue-shift of the Mn2+ emission. (C) 2003 Elsevier Science B.V. All rights reserved.