Alkali metal cyclopentadienide salts are important reagents in organometallic chemistry, having been used to prepare innumerable cyclopentadienyl complexes. Potassium cyclopentadienide, KCp, is usually made by deprotonation of cyclo-pentadiene with potassium metal either in organic solvents such as THF and benzene or in liquid ammonia. Both NaCp and KCp can be obtained in a one-pot synthesis directly by the reaction of dicyclopentadiene with the respective alkali metal without using any other solvent. This procedure is much more convenient, does not require dry solvents such as THF or decahydronaphthalene, and produces a product free of colored impurities. This chapter discusses the procedure and properties for sodium cyclopentadienide and potassium cyclopentadienide. © 2014 by John Wiley & Sons, Inc. All rights reserved.