This volume constitutes the refereed proceedings of the 15th International Conference on Conceptual Modeling, ER '96, held in Cottbus, Germany, in October 1996. The volume presents three invited contributions together with 29 revised full papers selected from 110 submissions. The papers cover all current aspects of the entity-relationship approach and conceptual modeling; they are organized in sections on advanced schema design, processes, query languages, representation, integration, principles of database design, transformation, enhanced modelling, capturing design information, and evolution.