In the present study, Indium Phosphide (InP) (100) samples with a thickness of ~ 0.5 mm have been bombarded with 1.5 keV Argon atoms for a fixed fluence of 8 × 10 16 atoms/cm 2 . The angle of incidence of the atom beam has been varied from normal incidence to 76° with respect to surface normal. The bombarded surface shows the nanostructures as analysed by Atomic Force Microscopy (AFM). For normal and near normal incident angles of the beam, nanodots pattern have been observed and after a critical angle of incidence, the dots begin to align and with further increase of angle, nanostructures elongate along the beam direction. At 63° incidence, a well ordered ripple pattern has been reported. The evolution of nanostructures from nanodots to nanoripples has been analysed in terms of their size, shape and roughness by means of AFM imaging.