Copper belongs to those metals whose concentrations in nature arise from a broad diversity of endogeneous and exogeneous pro­ cesses, which applies to essentially all genetic classes of ore deposits. This is the first proceedings volume on copper metallogeny to cover the worldwide distribution of the four main groups of cop­ per deposits, including in Part I: copper-nickel deposits with cobalt and platinum group elements; Part II: copper-molybde­ num-gold deposits with silver, zinc, and lead; Part III/IV: copper­ zinc-lead deposits (with silver etc.). On the occasion of the 27th International Geological Congress in Moscow, USSR, a symposium on copper metallogeny was held, dealing with metallogenesis and mineral deposits. The symposium was organized and sponsored by three international societies en­ gaged in the field of ore deposits: The Society of Economic Geol­ ogy (SEG), the Society of Geology Applied to Mineral Deposits (SGA) and the International Association on the Genesis of Ore Deposits (IAGOD). Invited papers were presented in four ses­ sions: (1) Copper deposits in mafic and ultramafic complexes, (2) Porphyry copper deposits, (3) Copper deposits of volcanic-hydro­ thermal association, and (4) Sediment-hosted copper deposits. The sessions were chaired by A. D. Genkin, A. J. Naldrett, J. D. Ridge and G. I. Gorbunov; V.1. Sotnikov, A. Soregaroli, R. H. Sillitoe and V. A. Evstrakhin; F. M. Vokes, A.1. Krivtsov, M. Solomon and N. I. Eremin; G. H. Friedrich, Yu. V. Bogdanov, A.C. Brown and F.P. Krendelev.