The coordination chemistry of vanadium with its variety of oxidation states has been the subject of extensive research mainly due to two type of activity: biological and catalytic. Recently, a number of vanadium(V) complexes with bis-hydrazone ligands exhibited high catalytic activity in alkane oxidation reactions [1-2]. As a part of the study of coordination behavior of carbohydrazone based ligands, we are extending our research on the synthesis of vanadium complexes. This work describes the preparation and structural characterization of dinuclear dioxovanadium(V) complexes (NH4)[(VO2)(H2L1-2)]·CH3OH (1-2), which involve the symmetrical Schiff base ligands 1,5-bis(salicylaldehyde)carbohydrazone (H2L1) and 1,5-bis(5-methyl-salicylaldehyde)carbohydrazone (H2L2). Vanadium complexes were prepared by treating methanolic solution of the corresponding ligand with two equivalents of NH4VO3. Single-crystal X-ray diffraction analyses reveal that complexes 1−2 are isostructural. As shown in Fig. 1 the ligand H2L1 acts as a triply-deprotonated base in the enolic form anti bonding to two cis-VO2 moieties through two tridentate units ONO and ONN, respectively. Each vanadium(V) ion is five-coordinate in a tetragonal pyramidal environment, with the doubly bonded oxygen O(1)and O(2) and O(6) and O(7) in the apex.