The morphometric analysis for the present study area helps to understand the relation and variation of major sub-watersheds in Aiyar and Karai-Pottanar basin, Tamil Nadu. The study area is classified into four sub-watersheds, namely SWS-I, SWS-II, SWS-III, SWS-IV. Different morphometric parameters were used to understand the drainage characteristics. Shuttle Radar Topographic Mission (SRTM), data were used to prepare the Digital Elevation Model (DEM), Aspect grid, Drainage network and Slope maps in ArcGIS platform. The stream order in the sub-watersheds ranges from fifth to seventh order. The drainage pattern in the study area exhibits dendritic to sub-dendritic pattern. The mean bifurcation ratio varies between 3.03 to 4.39 and falls under normal basin category. High bifurcation ratio determines that the region is subjected to strong structural control on the drainage. Drainage density shows coarse drainage and texture shows fine drainage texture. The elongation ratio varies between 0.65 to 0.89, in which SWS-II shows oval shape and rest other shows elongation pattern. Hence from the present study, the geospatial techniques play a vital role in understanding and evaluating the basin characteristics.