Molybdenocene and tungstenocene complexes have played a prominent role in the development of organometallic chemistry. This chapter describes the synthesis of (η5-C5Me5)2MoCl2 and (η5-C5Me5)2MoH2. (η5-C5Me5)2MoCl2 is obtained by a two-step sequence involving (i) the reaction of MoCl5 with a mixture of KC5Me5 and NaBH4 to give crude (η5-C5Me5)2MoH2, followed by (ii) addition of CHCl3. (η5-C5Me5)2MoCl2 is a useful precursor for a variety of other permethylmolybdenocene derivatives, which include hydride, alkyl, carbonyl, and oxo complexes.