This paper describes an ethylene glycol (EG)-assisted approach to the ultralong Sb2S3 nanowires, formed by a simple hydrothermal reaction between SbCl3 and Na2S in the presence of distilled water. Transmission electron microscopy and scanning electron microscopy studies indicate that these Sb2S3 nanowires possess a diameter around 200 nm and length up to 100 μm. High-resolution transmission electron microscopy and selected area electron diffraction studies reveal that each Sb2S3 nanowire is a single-crystal along the [001] direction. The possible formation mechanism of the nanowires was discussed. The effects of volume ratio of ethylene glycol/water on the morphology of Sb2S3 nanowires were also investigated. Diffuse reflectance spectrum result shows that the final products have an apparent blue shift by quantum size effect.