The application of psychology in the design of systems is not new, and began in earnest after the Second World War with the formation of the Human Factors Society in the USA and the Ergonomics Society in the UK. What has changed very recently is the growing interest in the area of engineering psychology, as exemplified by a number of new developments, These include the Ist International Conference on Engineering Psychology and Cognitive Ergonomics held at Stratford-upon-Avon, UK, in October 1996, the formation of a Special Interest Group on Engineering Psychology within the British Psychological Society, and the launch of a new US journal in 1997-the International Journal of Cognitive Ergonomics. This article considers some of the major accidents which have occurred in recent years, and the contribution which engineering psychology makes to designing systems and enhancing safety.