In recent years there has been a movement in drug discovery and development away from chemical processes that produce racemic compounds towards those that produce stereochemically defined products. Asymmetric reactions are an attractive way to produce such products. Here, I discuss the factors that are important in deciding whether using an asymmetric reaction is the most appropriate approach for the large-scale synthesis of a stereochemically defined pharmaceutical compound, and highlight progress in the development of large-scale stereoselective processes.