A series of square planar [Pt(N^C)(NHC)L] complexes containing cyclometallated N^C ligands (phenylpyridine and benzoquinoline) and N-heterocyclic carbene (NHC): N^C = 2-phenylpyridine, 7,8-benzoquinoline; NHC= 1,3-dibenzylbenzimidazolium, 1,3-diethylbenzimidazolium, 1,3-dibenzylimidazolium; L = Cl, Br, -C2Ph; has been synthesized in moderate to good yield. The complexes obtained were characterized using chemical analysis, MS-ESI spectrometry, NMR spectroscopy and X-ray crystallography. The complexes display moderate to strong phosphorescence in solution (Q. Y. 0.3-7.9 %) and in solid state (Q. Y. 2.7-16.0 %), which are related to metal modulated intraligand π-π* transitions located at aromatic system of cyclometallated ligands with some contribution of MLCT excited state. Emission lifetimes fall in the range 0.2-1.5 µs in solution and amount up to 13 µs in solid state. Analysis of the spectroscopic data together with the density functional theory (DFT) and time-dependent density functional theory (TD DFT) calculations clearly support this assignment and show negligible contribution of the auxiliary ligands into emissive excited states. The compounds obtained were also used to prepare organic light emitting diode (OLED) devices, which display good luminance efficiency emitting in green area of the visible spectrum. π