The basic properties of molybdenum and subsequently the methods of producing metallic molybdenum are described. Selected classes of important inorganic compounds (molybdenum halides, molybdenum oxides, iso- and hetero-polyoxomolybdates) as well as molybdenum hexacarbonyl and hybrid inorganic–organic materials are presented. Thereafter the focus is directed to various applications of metallic molybdenum, its alloys and compounds such as catalysts, lubricants and refractory ceramics. In conclusion, molybdenum’s medicinal role and the antimicrobial activity of MoO3 and solid solutions Mo n W1-n O3 are discussed.