Ab initio band structure calculations have been carried out to find the pressure-induced structural transitions and stability of praseodymium oxide (PrO 2 ) in cubic and orthorhombic phases .The first principle tight-binding linear muffin-tin orbital method (TB-LMTO) within local density approximation (LDA) has been used to study the electronic band structure of PrO 2 under pressure. Reported here, apart from the energy band calculations, is the density of states (DOS) and Fermi energy (E f ) at various high-pressure phases. The lattice parameter, transition pressure, bulk modulus and the pressure–volume relation have also been calculated.