Treatment of [Cp2LnNHPy]2 (Py = 2-pyridyl) (1) with 4-nitrophenyl isocyanate gives the unexpected complexes Cp2Ln[η2:η1-PyNCON(C6H4NO2-4)CONHC6H4NO2-4] (Ln = Yb (5a), Er (5b)) as the main product regardless of the equivalency of isocyanatereagent employed. The more bulky isocyanate (2,6-iPr2C6H3NCO) also undergoes double insertion into 1, affording Cp2Ln[η2:η1-PyNCON(C6H3iPr2-2,6)CONHC6H3iPr2-2,6]