Pyrrolidinothiocarbonyl groups promote cyclorhodation of an aromatic ring with [RhCl3(PBu3)2] (PBu3= tri-n-butylphosphine): thus p-(l-pyrrolidinothiocarbonyl)toluene (Htpr). 2-(l-pyrroli-dinothiocarbonyl)naphthalene (Hbnr), 2-(l-pyrrolidinothiocarbonyl)benzo[b]thiophene (Htnp) and l,3-bis(l-pyrrolidinothiocarbonyl)benzene (Hmpr) gave, respectively, [RhCl2(tpr)(PBu3)2], [RhCl2(bnr)(PBu3)2], [RhCl2(tnp)(PBu3)2], and [RhCl2(mpr)(PBu3)2]. These complexes were characterized spectroscopically. The two PBu3ligands aretransto each other and the thioamides behave as uninegative, bidentate C-S donors. Htpr was rhodated at theorthoposition, Hbnr at position 3, Htnp at position 3, and Hmpr at position 4 against the expected position 2 in which case it could act as an S-C-S terdentate ligand. Reactions of Htpr, Htnp, and Hbnr with RhCl3(H2O)3gave no definite cyclorhodated product but Hmpr afforded [RhCl2(mpr)(H20)] where mpr was cyclorhodated at position 2 and chelated as an S-C-S terdentate ligand.