A simplified super-CI technique is presented, which is used to solve the orbital optimization problem in the Complete Active Space SCF method (CASSCF). All super-CI matrix elements are expressed in terms of an average Fock operator, where the major parts can be obtained directly from the AO integrals. Only a relatively small number of transformed two-electron integrals are needed, thus reducing the transformation bottleneck in MCSCF to an absolute minimum. Since all matrix elements are given in terms of first-and second-order reduced density matrix elements with indices restricted to a small active subspace of the orbital space, the super-CI calculation becomes independent of the length of the CI expansion. This is an important aspect, since the complete active space CI expansion can include many terms. The method is demonstrated in a calculation of potential curves for the three lowest states of the N2 molecules, and some equilibrium properties of the water molecules. The following results were obtained for N2 for the states 1Σ+g, 3Σ+u and 3Πg; De: 9.04 (9.90), 2.71 (3.68), and 3.86 (4.89) eV;re: 1.109 (1.098), 1.309 (1.287), and (1.213) A; (experimental values in parenthesis). For H2O it was demonstrated that a balanced calculation around the equilibrium geometry must use eight active valence orbitals. The results are re: 0.964 (0.957) A; θe: 104°.8 (1.4°.5); dipole moment: 1.98 (1.86) debye; quadrupole moment: 2.64, −2.51, −0.13 (2.63, −2.50, −0.13) × 10−26 esu cm2.