We report the first use of parameter-free norm-conserving pseudopotentials for a strongly spin-polarized material, ferromagnetic bcc iron. Ground-state properties such as the equilibrium lattice constant, magnetic moment, and bulk modulus are calculated within the local-density-functional approximation and agree within a few percent with experiments. The deviations are, however, significantly larger than what is typically found for materials with s,p electrons. © 1983 The American Physical Society.