In this paper we report a new ground state potential energy surface for ethylene (ethene) C2H4 obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82 542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally-computed vibrational levels of the C2H4 molecule was obtained with a RMS(Obs. − Calc.) deviation of 2.7 cm −1 for fundamental bands centers and 5.9 cm −1 for vibrational bands up to 7800 cm −1. Large scale vibrational and rotational calculations for 12C2H4 , 13C2H4 and 12C2D4 isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm −1 are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of 13C2H4 and 12C2D4 and rovibrational levels of 12C2H4 .