This book constitutes the refeered proceedings of the First International Workshop on Service Assurance with Partial and Intermittent Resources, SAPIR 2004, held in Fortaleza, Brazil in August 2004.The 28 revised full papers presented were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on bandwidth allocation, policy-based operations, service monitoring, intelligent architectural systems, mobility and wireless, protocol mechanisms, and performance across domains.