MnO/C nanocomposites are successfully fabricated via a facile in situ interfacial polymerization followed by carbonization. The MnO/C nanocomposite exhibits unique one-dimensional core–shell nanostructure with an average diameter of 50nm and a ∼10nm thick carbon shell that uniformly encapsulates the MnO core. When used as an anode material for lithium-ion batteries, the MnO/C composite nanowire shows a high reversible capacity of 903mAhg−1 at 100mAg−1 after 100 cycles and a high-rate specific capacity of 483mAhg−1 even at 2Ag−1. In addition, the MnO/C anode demonstrates excellent recoverability when cycled at different cut-off voltages ranging from 1.5 to 3.0V. The scalability and outstanding Li-ion storage properties enable the present synthesis strategy to open up the possibility of fabricating MnO/C nanocomposites for high-performance lithium-ion batteries.