Field emission has been demonstrated from silicon that has been ionimplanted with carbon and nitrogen. Self-assembled silicon nanostructures were prepared as a template on the surface of wafer silicon, prior to multiple low-energy ion implantations. Following ion implantation, the original surface nanostructuring was lost. However, after electron beam annealing, selfassembled surface nanostructures were observed. Nuclear reaction analysis and Rutherford backscattering spectrometry indicated a Si 0.6 C 0.1 N 0.3 layer extending to a depth of $120 nm. Electron emission was measured from the as-implanted and post-annealed samples. The implanted and annealed sample showed a low turn-on field of 10 V/lm compared with 44 V/lm for the as-implanted sample.