Desalination plants are mostly manufactured from metallic materials and corrosion plays an important part in determining their life and reliability. The primary interest of plant designers and operators is to minimise corrosion in order to improve life and reliability, and less emphasis has been placed on the effects of corrosion products on the environment. This paper reviews known information on the corrosion behaviour of alloy materials in two important desalination processes, namely reverse osmosis (RO) and multi-stage flash (MSF) and considers the environmental effects of corrosion products. The main materials considered are the copper base alloys such as copper-nickels, and stainless steels. Details of alloy composition are given in Table 1. Both these groups of materials are used in large amounts in desalination processes.