Dicalcium phosphate cements were developed two decades ago and ever since there has been a substantial growth in research into improving their properties in order to satisfy the requirements needed for several clinical applications. The present paper presents an overview of the rapidly expanding research field of the two main dicalcium phosphate bioceramics: brushite and monetite. This review begins with a summary of all the different formulae developed to prepare dicalcium phosphate cements, and their setting reaction, in order to set the scene for the key cement physical and chemical properties, such as compressive and tensile strength, cohesion, injectability and shelf-life. We address the issue of brushite conversion into either monetite or apatite. Moreover, we discuss the in vivo behavior of the cements, including their ability to promote bone formation, biodegradation and potential clinical applications in drug delivery, orthopedics, craniofacial surgery, cancer therapy and biosensors.