Single-crystalline A]GaN:Mn nanotubes (see figure) with a an outer ameter less than 200 nm and a length of a few micrometers are prepared by a chloride-based chemical vapor deposition process. The nanotubes exhibit room-temperature ferromagnetism. without evidence of a ferromagnetic transition, showing that the structural and compositional modulation of 1D nanostructures could open up a way of exploring new classes of diluted magnetic semiconductors.