Terahertz (THz) technology is now drawing increasing attention around the world; it has been considered as an efficient non-destructive, non-contact and label-free optical method for biological detection. In this field, nanomaterials and nanostructures have been constantly advancing the development of THz technology. Here, we proposed some latest applications of nanotechnology to improve THz biological detection capability for providing progressive THz systems, thus enabling outstanding detection performance utilizing THz spectroscopy and imaging; these will encourage broader interest in various fields. The uniqueness, limitations, and future prospects of THz biological applications based on nanomaterials and nanostructures will also be reviewed in light of recent developments.