This book constitutes the refereed proceedings of the 8th International Workshop on Interactive Distributed Multimedia Systems, IDMS 2001, held in Lancaster, UK, in September 2001. The 15 revised full papers and 8 short papers presented together with 3 abstracts of invited talks were carefully reviewed and selected from 48 submissions. The book offers topical sections on media distribution, QoS issues in multimedia, multimedia middleware, congestion control and adaptation, and control of multimedia networks.