The dehydrocoupling of primary phosphines with N-heterocyclic carbenes (NHCs) to yield NHC-phosphinidenes is reported. The reaction of two equivalents of the NHCs Me 2 Im (1,3dimethylimidazolin-2-ylidene), Me 4 Im (1,3,4,5-tetramethylimidazolin-2-ylidene), iPr 2 Im (1,3-di-iso-propylimidazolin-2ylidene) and Mes 2 Im (2,4,6-trimethylphenylimidazolin-2-ylidene) with PhPH 2 and MesPH 2 led to the NHC stabilized phosphinidenes (NHC)PAr: (iPr 2 Im)PPh ( 1), (Mes 2 Im)PPh ( 2), (Me 4 Im)PPh ( 3), (Mes 2 Im)PMes ( 4), (Me 2 Im)PMes ( 5), (Me 4 Im)PMes ( 6) and (iPr 2 Im)PMes ( 7). The reaction of tBuPH 2 with two equivalents of the NHCs afforded the corresponding NHC stabilized parent phosphinidenes (NHC)PH: (iPr 2 Im)PH ( 8), (Mes 2 Im)PH ( 9) and (Me 4 Im)PH (10). Reaction of 1 with oxygen and sulfur led to isolation of iPr 2 Im-P(O) 2 Ph (11) and iPr 2 Im-P(S) 2 Ph (12), whereas the reaction with elemental selenium and tellurium gave (NHC) PPh cleavage with formation of (iPr 2 Im)Se ( 13), iPr 2 ImTe (14) and different cyclo-oligophosphines. Furthermore, the complexes [{(iPr 2 Im)PPh}W(CO) 5 ] (15), [Co(CO) 2 (NO){(iPr 2 Im)PPh}] (16) and [(η 5 -C 5 Me 5 )Co(η 2 -C 2 H 4 ){(iPr 2 Im)PPh}] (17) have been prepared starting from 1 and a suitable transition metal complex precursor. The complexes 16 and 17 decompose in solution upon heating to ca. 80°C to yield the NHC complexes [Co(iPr 2 Im)(CO) 2 (NO)] and [(η 5 -C 5 Me 5 )Co(iPr 2 Im)(η 2 -C 2 H 4 )] with formation of cyclo-oligophosphines. The reaction of 1 with [Ni(COD) 2 ] afforded the diphosphene complex [Ni(iPr 2 Im) 2 (trans-PhP = PPh)] 18.