This volume constitutes the proceedings of the Third IFIP WG 8.1 Working Conference on the Practice of Enterprise Modeling, held in Delft, The Netherlands, during November 9-10, 2010. The goal of the conference is both to foster a better understanding of the practice of enterprise modeling and to improve its theoretical foundations.The 17 papers presented were carefully reviewed and selected from 44 submissions. They reflect interests of both practitioners and academics, addressing domains and conceptualizations of dedicated business-oriented topics such as business intelligence or domain-driven process families, and thus reaching beyond traditional information systems engineering.