In this current research article, the structural elasto-mechanical and thermal properties of cubic perovskites XCoO 3 (X = Nd, Pr) have been studied theoretically under different pressures. The structure is optimized and calculated optimized data is in well agreement of available literature. All these calculations are performed by considering Perdew Burke Ernzerhof Generalized Gradient Approximation type exchange and correlation functional within Wien2k-code. The second order cubic independent elastic constants C 11 , C 12 and C 44 are computed by using this optimized data. The dynamical stability criteria is checked by computed constants and used to find the elastic moduli; shear, Young's and Bulk modulus. The other mechanical properties like Poisson's ratio, anisotropic factor, Pugh's ratio, shear constant, Cauchy pressure, Lame's constants, Kleinmann parameter are quantified and discussed. The results portray the ductility of XCoO 3 (X = Nd, Pr) perovskites and utility in high temperature devices.