The different ways in which gold alloys can deteriorate are described. The principal alloys discussed are gold-copper, gold-silver and gold-copper-silver. Examples of South American gold alloys from Colombia and Panama are used to illustrate the different types of corrosive attack. Some problems related to the conservation of gold alloy antiquities are mentioned, together with the difficulty of the preservation of technological evidence. See also AATA 20-2196 and 20-2197.