M(NMe2)(4) (M = Zr, 1a; Hf, 1b) and the silyl anion ((SiBuPh2)-Ph-t)(-) (2) in Li(THF)(2)(SiBuPh2)-Ph-t (2-Li) were found to undergo a ligand exchanged to give [M(NMe2)(3)((SiBuPh2)-Ph-t)(2)](-) (M = Zr, 3a; Hf, 3b) and [M(NMe2)(5)](-) (M = Zr, 4a; Hf, 4b) in THF. The reaction is reversible, leading to equilibria: 2 1a (or 1b) + 2 2 <-> 3a (or 3b) + 4a (or 4b). In toluene, the reaction of la with 2 yields [(Me2N)(3)Zr((SiBuPh2)-Ph-t)(2)]-[Zr(NMe2)(5)Li-2(THF)(4)](+) (5) as an ionic pair. The silyl anion 2 selectively attacks the -N(SiMe3)(2) ligand in (Me2N)(3)Zr-N(SiMe3)(2) (6a) to give 3a and [N(SiMe3)(2)]-(7) in reversible reaction: 6a + 2 2 <-> 3a + 7. The following equilibria have also been observed and studied: 2M(NMe2)(4) (1a; 1b) + [Si(SiMe3)(3)]- (8) <-> (Me2N)(3)M-Si(SiMe3)(3) (M = Zr, 9a; Hf, 9b) + [M(NMe2)(5)](-) (M = Zr, 4a; Hf, 4b); 6a (or 6b) + 8 <-> 9a (or 9b) + [N(SiMe3)(2)](-) (7). The current study represents rare, direct observations of reversible amide-silyl exchanges and their equilibria. Crystal structures of 5, (Me2N)(3)Hf-Si(SiMe3)(3) (9b), and [Hf(NMe2)(4)](2) (dimer of 1b), as well as the preparation of (Me2N)(3)M-N(SiMe3)(2) (6a; 6b) are also reported.