The application of the density-functional theory in the local approximation to magnetic materials is discussed and illustrated by examples. The magnetic properties of the 3d elemental metals as well as their cohesive properties are described by means of self-consistent local-spin-density (LSD) calculations and by using the LSD-Stoner method. The application of the LSD approximation to narrow-band compounds (3d-monoxides) and to lanthanum cuprate indicates that correlation effects beyond those included in the LSDA must be added in order to obtain a realistic description of the ground state. The LSDA fails in predicting the antiferromagnetic ground state of La2CuO4.
 

Journal de Physique Colloque, 49 17-22, 1988.