This chapter focuses on development non-governmental organisations (NGOs) and consider three aspects of their relationship with management science. It explores the traditional ambivalence that many development NGOs have felt towards management and discuss the reasons. The chapter provides a brief overview of the fledgling field of “NGO management” itself, and outline some of its main concerns. It suggests a composite approach rather than viewing it as a distinct area of management, since its practice requires a spirit of improvisation. The study of management is a large and diverse field of research, with wide-ranging products that include theoretically informed academic research, normative texts, in-depth case studies and practical “self-help” books. Viewing NGOs in the context of management science makes more visible two basic dimensions of management that exist in tension – the expressive and the instrumental. The chapter concludes by making the case for mainstream management scholars to engage more fully with the field of NGOs than they have done before.