The purpose of this thesis is to explore how ESP learner needs have been perceived and answered in contemporary ESP programmes. It aims at providing some suggestions and implications regarding needs analysis, course design and the development of language skills. The first chapter introduces the concept of 'ESP ' and, therefore, attempts to unfold the debate which has surrounded its definition and its practices. This involves viewing the factors which have led to its development and which have set it apart of General Purpose English (GPE); investigating the theoretical background against which it has developed and, thus, questioning the validity of equating ESP with the learner's specialized subject-matter or specialist register; and considering the major types of ESP courses which have branched off ESP. The second chapter is concerned with the main changes that have occurred in ESP course design. It argues for a process-oriented approach since this type of syllabus, in its balanced form, accommodates the learner's real-world needs and process-learning needs. The process oriented movement has revolutionized the concept of 'learner needs'. The needs of the learner are not only viewed in terms of language items or course content but also in terms of the psychological aspects of the learning process and classroom learning behaviours. Chapter Three establishes a view of needs analysis and course design which takes the learner's perception of her needs as a starting point. This view is opposed to the needs analysis associated with Munby 's work (1978). It proceeds from the concept of 'need' and is built upon the ideas emerging from the process- oriented movement. It emphasises the centrality of the learner’s role in the needs analysis and course design procedures. Chapter Four represents a case study conducted at Dublin City University (D.C.U.). The study arose from a concern about how adult learners envisaged their needs and, thus, the extent to which they could act as informants regarding the content of the language course and the teaching-learning methodology. It was inspired by a belief that EAP learners are not necessarily instrumentally motivated and, therefore, their needs cannot be met by a course which proceeds from a target-situation needs analysis. In addition to supporting our assumption, the study has provided some insights into the nature of learner needs and learning styles and perceptions of teacher-learner role. Chapter Five aims at highlighting some of the subskills and strategies involved in each of the four skills with reference to specialized needs. It provides suggestions for selecting learning materials and some teaching implications. The final chapter discusses some conclusions about the implications which this research provides for ESP instruction and course design.