Experimental advances have sparked considerable interest among theorists to deal with chemisorption on noble and transition metalsurfaces. The localized nature of d‐orbitals and the importance of self‐consistency have made progress difficult. However there are now surface band calculations for chemisorbed layers which are of a quality comparable to modern bulk solid state calculations. These calculations are being used to explain photoemissionspectra with some success. Recent theoretical approaches and their limitations are reviewed and some results are compared with ultraviolet photoemissionspectra.