Four hydrazone ligands: 2-benzoylpyridine benzoyl hydrazone (HBPB), di-2-pyridyl ketone nicotinoyl hydrazone (HDKN), quinoline-2-carbaldehyde benzoyl hydrazone (HQCB), and quinoline-2-carbaldehyde nicotinoyl hydrazone (HQCN) and four of their complexes with vanadyl salts have been synthesized and characterized. Single crystals of HBPB and complexes [VO(BPB)(μ 2-O)] 2 ( 1) and [VO(DKN)(μ 2-O)] 2·½H 2O ( 2) were isolated and characterized by X-ray crystallography. Each of the complexes exhibits a binuclear structure where two vanadium(V) atoms are bridged by two oxygen atoms to form distorted octahedral structures within cis-N 2O 4 donor sets. In most complexes, the uninegative anions function as tridentate ligands, coordinating through the pyridyl- and azomethine-nitrogen atoms and enolic oxygen whereas in complex [VO(HQCN)(SO 4)]SO 4·4H 2O ( 4) the ligand is coordinated in the keto form. Complexes [VO(QCB)(OMe)]·1.5H 2O ( 3) and 4 are found to be EPR active and showed well-resolved axial anisotropy with two sets of eight line pattern.