Equilibrium geometries, energies, and vibrational frequencies of cage-shaped boric acid clusters including the onion-like structure have been calculated at the HF/6-31G and B3LYP/6-31G(d) levels of theory. A family of cage-shaped boric acid clusters becomes evident according to our calculations. Each member of the family is formed by strong O-(HO)-O-... hydrogen bonds. Higher cage-shaped boric acid clusters are more stable. The calculated stabilization energies for the cage-shaped boric acid clusters appear to steadily increase with the number of boric acid molecules (n) and are nearly linear in n. Similarities between ca.-e-shaped boric acid clusters and fullerenes are also discussed.