This article is an updating of the ESP survey written by Professor Peter Strevens for Language Teaching and Linguistics: Abstracts, Vol. 10, No. 3 of July 1977. The account given there of ESP's definitions, antecedents, theoretical bases and methodology has not been rendered obsolete by the passage of six years, and it remains a definitive statement. What is new in the present article refers to output and events since 1977, and also, with a greater or lesser degree of tentativeness, to the development of trends – especially those which may indicate that ESP is moving into a pre-final phase, or which hint at new directions for research and development. This article also owes a considerable debt to other overviews of ESP that have appeared since 1977, and particularly to the work of Pauline C. Robinson (1980), of the University of Reading's Centre for Applied Language Studies.