An uranium trimesate open framework is built up from trinuclear building blocks (μ(3)-OU(3)) connected to each other by tricarboxylate linkers to generate honeycomb-like 3D topology. This compound was solvothermally synthesized from low-valent uranium in an N,N-dimethylformamide solvent under an inert atmosphere, favoring stabilization of the tetravalent oxidation state, which is confirmed by X-ray photoelectron spectroscopy analysis.