In contrast to subjects such as mathematics and the sciences, it has been argued that technology education lacks a clear definition and a clearly defined knowledge base. This discursive article seeks to inform the debate by highlighting the matter of subject definition and in addition to examine the key issue of the knowledge which underpins technology education. The nature of the knowledge involved in technology education is explored by focusing on the types of knowledge (declarative/conceptual, procedural and conditional/strategic) that are required to secure full engagement with this subject. Drawing on extant literature on knowledge, the article takes technology as its focus and highlights the challenges this presents for teachers. A conceptual framework based on the presented evidence is included to show the relationships between knowledge and the skills, the problem-solving and the values that are integral to technology education. This article concludes that to be effective, technology teaching must be based upon an appropriate subject definition indicating what it is endeavouring to achieve. In addition the existence of such a specialist subject knowledge base must be fully acknowledged, and at the same time there must be full recognition of the need to draw upon relevant knowledge from other subject areas in an appropriate manner in order to inform classroom teaching of the subject. (Contains 1 figure and 1 table.)