Isomerization and translocation of double bonds inside a molecule are essential steps in a variety of catalytic processes. Monoisomerization and especially chain walking reactions enable the functionalization of a great variety of organic frameworks. The compounds thus obtained are widely used as fragrances, agrochemicals and intermediates in the pharmaceutical industry. The field of transpositional isomerization catalysis has long been dominated by complexes based on precious metals, such as rhodium 3 , iridium 4 , ruthenium 5 and palladium. However, representatives of base metal catalysts in this field have been fathomed. The early development of nickel-8 and cobalt-based isomerization catalysts as well as industrial application of the latter 10 represent some of the most established examples. Over the last years base metal catalysts based on nickel, 11 cobalt, and iron, have emerged in the field of alkene isomerization. Selected base metal catalysts for the isomerization of alkenes are depicted in Figure .