Electronic energies of one-electron excited states 1s22s22p2ns 4P, 1s22s22p2ns 2P, 1s22s22p2np 4S, 1s22s22p2np 2S, 1s22s22p2np 4P, 1s22s22p2np 2P, 1s22s22p2np 4D, 1s22s22p2np 2D, 1s22s22p2nd 4P, 1s22s22p2nd 2P, 1s22s22p2nd 4D, 1s22s22p2nd 2D, 1s22s22p2nd 4F, 1s22s22p2nd 2F of nitrogen-like ions with n=3-12 and Z=7-50 have been calculated. For all the aforementioned electronic configurations, fine-structure levels have been determined for states with different total momentum J. The comparison of theoretical results with the available experimental data shows that theory and measurements agree well. In particular, relative accuracy of 10-4 has been achieved in the electronic energy of N-like at Z > 10, while the typical deviation in the calculated fine-structure levels from experimental data is in the order of 10-2