Self‐consistent‐field wave functions have been obtained for tetrahedrane, cubane, and dodecahedrane with a flexible s, p basis set, (9s5p/4s), [4s3p/2s]. The CC and CH distances were optimized to 0.001 A. Ionization potentials have been computed both by the ΔSCF and the Koopmans’ Theorem methods. The full spatial symmetry was used in the calculations, and some of the required considerations for dodecahedrane are discussed.