Needs analysis and language for specific purposes (LSP) courses are inextricably intertwined. LSP courses aim to help learners function linguistically within a particular academic, professional, or workplace environment, and the course syllabus is based on analysis of the needs of the learners in relation to such environments. The analysis of learners' needs is thus a key process in the design and ongoing revision of the LSP syllabus. Such is the importance of needs analysis that it is generally seen as the defining characteristic of LSP. This entry discusses the importance of needs analysis in LSP, identifies trends in the practices and methodologies used, and examines how the results of needs analysis can be used to inform the design of the LSP syllabus. Although needs analysis is often viewed as essentially procedural, it is not without theory, nor is it devoid of controversy and debate. The final sections discuss the role of theory and issues in needs analysis.