This article provides an overview of issues relating to the use of knowledge by development organisations. It starts by exploring the various definitions of knowledge that exist in a world of many cultures and intellectual traditions, and the role of language. It considers their relationship with each other and with the many and varied ‘informational developments’ – information-related changes in work, culture, organisations, and technology across the world. It argues that these issues pose a number of fundamental strategic challenges to the development sector. The second part considers where, in practice, development organisations get their information and knowledge from and identifies problems with many of the channels used. Its conclusion is that most current practice consistently militates against the type of relationship and type of communication that are essential if development policy and practice is to be anything other than an imposition of external ideas, however well intentioned.