Biomaterials and tissue engineering are rapidly expanding fields for research and also commercial exploitation. A greater understanding of the interaction of materials with cells has allowed implant materials to be designed with the aim of promoting a specific biological response. Phosphate-based glasses are a unique group of materials that offer great potential for hard and soft tissue engineering. The move from passive inert implant materials to active degradable materials indicates that phosphate glasses may have a role in tissue engineering. Whilst significant work has been carried out to elucidate the structure of these materials, there is a paucity of data to correlate this information with the physical properties such as dissolution rate. This paper details some of the basic properties of these materials and how these may be exploited in the design of a biomaterial. Also a review of some of the current and potential clinical uses for these materials is included.