Accurate variational calculations are presented for highly excited vibrational bound states of N2O using different recently proposed ab initio and empirical potential energy surfaces. All these potential surfaces are expressed as series expansions in terms of internal displacement coordinates. Transformations of them into Simons, Parr and Finlan (SPF) and Morse expansion are also considered. The vibrational state calculations are performed using a set of curvilinear hyperspherical normal coordinates derived from Radau coordinates. The vibrational energies are compared with experimental data and the quality of the potential energy surfaces used is discussed.