In recent years, Quality by Design (QbD) has gained significant prominence in the pharmaceutical industry as an efficient way of designing and controlling processes used to make therapeutic products. At its heart, QbD seeks to identify an operating envelope within which production consistently satisfies a target product quality profile and thereby achieves the desired level of safety and efficacy. Such an approach is assisted by a range of Biochemical Engineering techniques which increase process and product understanding. This perspective describes how the principles of Quality by Design and developments in the field of Biochemical Engineering are providing the pharmaceutical sector with a toolbox of methods that enable efficient bioprocess development and manufacture. (C) 2011 Society of Chemical Industry