Gallium nitride nanowires coated with boron carbonitride layers were directly synthesized by thermal chemical deposition using the reaction of gallium, gallium oxide, boron oxide, and carbon nanotubes under an ammonia atmosphere. The average diameter is 30 rim, and the length is up to 1 mm. Less than 20 graphitic sheets coat the single-crystal line wurtzite-structured gallium nitride nanowires. The graphitic outerlayers are composed of boron, carbon, and nitrogen atoms with a ratio of about 1:2:1. The photoluminescence exhibits a broad band in the energy range 2.1-3.6 eV, suggesting a contribution of the emission from the graphitic boron carbonitride outerlayers.