This book constitutes the thoroughly refereed post-proceedings of the Second International Workshop on Ubiquitous Mobile Information and Collaboration Systems, UMICS 2004, held in Riga, Latvia in June 2004 as a CAiSE satellite workshop.The 13 revised full papers presented together with an invited paper were carefully selected during two rounds of reviewing and improvement. The papers presented are related to fields such as workflow systems, groupware and CSCW, event-based systems, software architecture, distributed database systems, mobile computing, ubiquitous information systems, peer-to-peer systems, etc. The papers are organized in topical sections on data and context management, coordination and control process modeling, and application frameworks.