Decarboxylases are very useful tools for the defunctionalization of organic molecules under very mild reaction conditions. They have been applied for the synthesis of alcohols, carboxylic acids, diamines, terminal olefins, and other important chemicals. Moreover, several decarboxylases catalyze the fixation of carbon dioxide, which makes them promising catalysts for the utilization of this resource. Interestingly, several decarboxylases show promiscuous activities such as enzymatic racemization and stereoselective hydration. Despite this very high synthetic potential, large-scale processes are still rare and are mostly limited to fermentative approaches or to small-volume products. This Minireview gives an overview of the several recent, very promising applications both for the synthesis of high-value fine chemicals and biogenic bulk products and summarizes chances and limitations of this emerging class of biocatalysts.