The Sorbonne University is very proud to host this year the oms Conference on Object Oriented Information Systems. There is a growing awareness of the importance of object oriented techniques, methods and tools to support information systems engineering. The term information systems implies that the computer based systems are designed to provide adequate and timely information to human users in organizations. The term engineering implies the application of a rigorous set of problem solving approaches analogous to those found in traditional engineering disciplines. The intent of this conference is to present a selected number of those approaches which favor an object oriented view of systems engineering. oms '98 is the fifth edition of a series of conferences. Starting in 1994 in London, this series evolved from a British audience to a truly European one. The goal is to build a world wide acknowledged forum dedicated to object oriented information systems engineering. This conference is organized with the aim to bring together researchers and practitioners in Information Systems, Databases and Software Engineering who have interests in object oriented information systems. The objective is to advance understanding about how the object technology can empower information systems in organizations, on techniques for designing effective and efficient information systems and methods and development tools for information systems engineering. The conference aims also at discussing the lessons learned from large scale projects using objects. The call for oms was given international audience.