Granitic rocks commonly develop exfoliation surfaces (also called as sheet joints), which are generally surfaceparallel fracture systems. These structures may form in response to: (i) exhumation processes in which erosion causes upliftment of buried rocks; (ii) physical weathering due to thermal expansion and contraction; (iii) groundwater-related chemical weathering, and (iv) tectonic deformation. Although these structures are interesting geological features giving insights into past geological processes1,2, they have several other implications for engineering geological applications and groundwater exploration. The exfoliation joints can transport large volumes of groundwater laterally for long distances in many directions. Geological mapping of these structures is possible only on cliff sections, whereas in the near surface they cannot be detected. Geophysical studies can greatly help in locating them in the subsurface. In this communication, we demonstrate the application of ground-penetrating radar (GPR) in detecting subsurface exfoliation joints in granite exposure area near Durgam Cheruvu, a micro-earthquake zone in Hyderabad (Figure 1). The findings would be helpful for planning underground excavation (e.g. construction of tunnels), modelling groundwater flow systems, and designing foundation structures of large-scale building structures.