The complex [Tc(CO)₃Cl(PPh₃)] reacts with the sodium salt of PhNC(OEt)SH to give the thiazetidine complex [Tc(CO)₂(PPh₃)₂{PhNC(OEt)S}](1). The complex [TcNCl₂(PPh₃)₂] reacts with an excess of the neutral ligand to give [TcN(Cl)(PPh₃){PhNC(OEt)S}](2). When the reaction is carried out in presence of the ligand salt the disubstituted complex [TcN{PhNC(OEt)S}₂](3) is obtained. The crystal structures of (1) and (2) were determined by X-ray crystallography and refined to conventional R factors of 0.0295 and 0.0649 respectively. Compound (1) is monoclinic, space group P2₁, with a= 12.825(5), b= 16.713(5), c= 9.480(5)Å, β= 94.29(3)°, and Z= 2. The technetium environment is distorted octahedral. Selected bond distances are: Tc–P(1) 2.423(1)Å, Tc–P(2) 2.456(1), Tc–S 2.529(1), Tc–N 2.228(5), and Tc–C 1.89(1)Å(mean). Compound (2) is triclinic, space group P, with a= 9.428(5), b= 10.237(5), c= 15.603(5)Å, α= 89.29(3), β= 102.74(3), γ= 115.61 (3)°, and Z= 2. The environment of Tc is distorted square pyramidal with the nidrido N atom as apex. Selected bond distances are: Tc–N (nitrido) 1.615(7), Tc–N (ligand) 2.135(7), Tc–S 2.375(3), Tc–Cl 2.366(2), and Tc–P 2.429(2)Å.