We report the synthesis of beta-phase Ga2O3 nano-ribbons by plasma immersion ion implantation (PIII) and rapid thermal annealing (RTA). Un-doped GaAs substrate was treated with PIII of nitrogen. RTA at 950 degreesC for 2 min produced clusters of single crystalline beta-Ga2O3 nano-ribbons. These nano-ribbons have thickness of around 30 nm and widths 60 nm to 2 mum. The nano-ribbons start off directly from Ga2O3 grains on the surface and they emit blue light. Nano-wire growth usually involves a vapour-liquid-solid process in which metallic particles act as a condensation catalyst. However, we believe that the present case is likely to involve a vapour-solid mechanism. (C) 2003 Elsevier B.V. All rights reserved.