Few-layer MoS2 nanosheets are successfully synthesized using a simple and scalable ultrasonic exfoliation technique. The thicknesses of the MoS2 nanosheets ares about 10 nm as measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The unique nanosheet architecture renders the high-rate transportation of sodium ions due to the short diffusion paths provided by ultrathin thickness and the large interlayer space within the MoS2 crystal structure (d(002) = 6.38 Å). When applied as anode materials in sodium-ion batteries, MoS2 nanosheets exhibit a high, reversible sodium storage capacity and excellent cyclability. The MoS2 nanosheets also demonstrate good electrochemical performance at high current densities.