Conceptual modeling has long been recognized as the primary means to enable software development in information systems and data engineering. Conceptual modeling provides languages, methods and tools to understand and represent the application domain; to elicit, conceptualize and formalize system requirements and user needs; to communicate systems designs to all stakeholders; and to formally verify and validate systems design on high levels of abstraction. Recently, ontologies added an important tool to conceptualize and formalize system specification. The International Conference on Conceptual Modeling – ER – provides the premiere forum for presenting and discussing current research and applications in which the major emphasis is centered on conceptual modeling. Topics of interest span the entire spectrum of conceptual modeling, including research and practice in areas such as theories of concepts and ontologies underlying conceptual modeling, methods and tools for developing and communicating conceptual models, and techniques for transforming conceptual models into effective implementations. The scientific program of ER 2009 features several activities running in parallel.