In this chapter we review OR literature applied to hospital wards. Based on logistical characteristics and patient flow problems, we distinguish the following particular ward types: intensive care, acute medical units, obstetric wards, weekday wards, and general wards. We analyze typical trade-offs of performance measures for each ward type, and the common OR models applied to it. Additionally, we provide four modeling examples, discuss reported experiences with implementation of the research, and provide directions for future research. With this review we aim to guide both researchers and healthcare professionals in identifying which OR technique/model suits best for each specific hospital ward setting, and in actual implementation of the results in healthcare practice.