Reaction of pyrrole-2-aldehyde thiosemicarbazone (abbreviated as H₂L, where H₂ stands for the two potentially dissociable protons) with [Pd(PPh3)2Cl2] in ethanol in the presence of NEt3 afforded two complexes, [Pd(PPh₃)(HL_NS)Cl] and [Pd(PPh3)(LNNS)], where the thiosemicarbazone ligand is coordinated to the metal centre respectively as monoanionic N,S-donor (depicted by HL_NS) and dianionic N,N,S-donor (depicted by L_NNS). Similar reaction with Na2[PdCl4] afforded a bis-complex, [Pd(HL_NS)₂]. Crystal structures of all the three complexes have been determined.With reference to the structure of the uncoordinated thiosemicarbazone (H₂L), the N,S-coordinationmode observed in [Pd(PPh₃)(HL_NS)Cl] and [Pd(HL_NS)₂] is associated with a geometrical change around the imine bond.While the N,N,S-mode of binding observed in [Pd(PPh₃)(L_NNS)] takes place without any such geometrical change. All three complexes display intense absorptions in the visible and ultraviolet regions, which have been analyzed by TDDFT method.