An overview of the procedures to be adopted in selecting materials for use in ship structures is given. In general, materials are selected on a cost basis to meet a `basket' of mechanical properties such as stiffness, strength and fracture toughness. Such a selection procedure may well not give sufficient importance to the dynamic loading of the structure (fatigue), the special problems associated with the joining (welding) process and the influences of the conjoint effects of corrosion. At this stage, these effects are given scant attention, although it is clear that they need to be incorporated into the design process. Methods by which these influences may be incorporated into a design data base are reviewed based on an analysis of ships which have failed and experiments designed to simulate the total environment in which a ship operates.