Increasingly, formal specification is being used by database researchers to describe and understand the systems they are designing and implementing. Similarly, those working on formal specification techniques have recognized that the database field provides a rich context for developing their ideas. However, as experts in one field often have a relatively limited knowledge of the other, there is a growing need for discussion about the relationship between these two fields and how they can be usefully combined. This volume contains the 16 papers which were presented at the International Workshop on Specification on Database Systems, held in Glasgow, 3-5 July 1991. The purpose of the workshop was to bring together these fields and to examine, through a series of invited talks, presentations and working groups, the role that formal specification can play in developing database systems. The papers describe current research into topics such as the formal specification of data models, query languages and transaction handling and the use of formal specification techniques to understand problems which arise in database systems. The working groups, which are summarized at the end of the volume, covered a variety of issues including the role of graphical notations in database specification, the use of specification techniques in enabling open or extensible database systems and the education of the database community in specification techniques.