We use first principles calculations to investigate the effects of edge modification with nonmetal species on zigzag-edged BC2N nanoribbons (ZBC(2)NNRs). These ZBC(2)NNRs show either semiconducting or metallic behaviors depending on the edge modifications and ribbon widths. We find that the O-modification induces a ferromagnetic ground state with a metallic behavior for all the ribbon widths investigated. And when the ribbon width is more than 3.32 nm (N-Z >= 16), an antiferromagnetic ground state with a half-metallic behavior is realized in the H-passivated ZBC(2)NNRs. These versatile electronic properties render the ZBC(2)NNRs a promising candidate material in nanoelectronics and nanospintronics. (C) 2016 Elsevier B.V. All rights reserved.