This chapter describes the nine SysML diagrams. Following this introduction, the terminology used throughout the chapter is explained and the structure of SysML diagrams is discussed. This is followed by a discussion of stereotypes and then of the SysML meta-model, which forms the basis of this chapter. Following this, each of the nine diagrams is described in turn. For each diagram type there is a brief introduction, a discussion of the diagram elements through its meta-model and notation, examples of how to use the diagram and a summary.