The oxozirconium clusters Zr₆O₂(OPr)₁₆(OOC–C₁₀H₆O)₂(PrOH)₂ and Zr₁₀O₆(OH)₄(OOC–C₆H₄OH)₈(OOC–C₆H₄O)₈· 6 PrOH were obtained in quantitative yield, when Zr(OPr)₄ was reacted with a 10-fold excess of 1-hydroxy-β-naphthoic acid and salicylic acid, respectively. The naphthoate-substituted cluster has a rather open structure, the dianion of 1-hydroxy-β-naphthoic acid acting as a tetradentate ligand. The carboxylate group chelates one zirconium atom, and one oxygen of the carboxy group and the aryloxy group chelate a neighboring zirconium atom. In contrast, the structure of the salicylate-substituted cluster is highly condensed and contains the octahedral Zr₆O₄(OH)₄ core also found in other oxozirconium clusters. Four salicylate ligands bridge edges of the Zr₆ octahedron via their COO group; their phenolic OH groups do not coordinate to a metal atom. The other eight salicylate ligands are dianionic. Each of them bridges an edge of the Zr₆ octahedron via their COO group and additionally chelates one of the zirconium atoms condensed to the Zr₆ cluster core by their phenolate oxygen and one of the oxygen atoms of the COO group.