Mechanical cables have long been used for towing, for remote control or for the supplying of communication or other service links between two vehicles. They also constitute the basic structural element in suspended bridges. On the other hand they are used in biomedical engineering applications; to lower men underground as deep as 16,000 ft and they are considered in superconductivity applications. Obviously the problem of evaluating the “structural health” of cables or ropes by means of non-destructive test methods is of the utmost importance. This article is concerned with a survey of the available methods.