The difference between peptides and proteins (the subject of Chapter 2) is that peptides are molecules too small to have a “globular” structure. This means that the spectral assignment process is often much simpler for peptides than it is for proteins, because there are fewer signals present in peptide spectra; on the other hand, peptides seldom adopt a single, well defined structure in solution, which makes the interpretation of structural data more contentious for peptides than it is for proteins. The emphasis in this chapter is therefore different from that in Chapter 2. The acquisition of structurally relevant data is straightforward, given a familiarity with modern two-dimensional (2D) NMR techniques and is given less emphasis here, but the analysis of the data is seen as the key to obtaining a meaningful answer, and is the area where experience and expertise are most necessary.