For the H2COH radical, properties such as geometries, frequencies, electric and magnetic dipole moments, electronic and ionization spectra, etc., were investigated at the ab initio level (second-order Moeller-Plesset and multireference configuration interaction (MRD-CI) methods). At equilibrium, H2COH (sigma(2) pi(2)n(2) pi*) is of C-1 symmetry. The inversion and rotation conformations are about 1 and 5 kcal/mol less stable. The MRD-CI vertical ionization potentials (eV) lie at 7.89 (pi* --> infinity) and 12.91 (n --> infinity, into 1(3)A " of the cation). The pi* --> 3s state (adiabatically at T-e approximate to 3.23 eV, calculated) is placed about 1 eV lower than previously assumed. Experimental T-0＇s of 4.34 and 5.09 eV are respectively reassigned to pi* --> 3p(z) and pi* --> 3p(x) (perpendicular and parallel bands relative to the CO bond). At the equilibrium geometry, the valence states lie at 6.46 (n --> pi*), 7.30 (pi --> pi*), and 8.40 eV (sigma --> pi*); i.e., the latter lies in the ionization continuum. The direction of the electric dipole moment of H2COH is mainly governed by the OH bond. The electron-spin magnetic moment (g factor) was evaluated via a perturbative approach complete to second order, using a Breit-Pauli Hamiltonian. The largest second-order contributions to Delta g are due to sigma --> pi* and n --> pi*. At the ROHF level, Delta g(av) = g(av) - g(e) is similar to 500 ppm for both the equilibrium and inversion conformations and near 300 ppm for the rotation geometry. Correlated values are estimated : to be similar to 150 ppm higher. Experimental studies for H2COH in solution find Delta g(av) approximate to 1000 ppm.