This book constitutes the refereed proceedings of the 4th International Symposium on Mobile Human-Computer Interaction, Mobile HCI 2002, held in Pisa, Italy in September 2002. The revised 18 full papers and 32 short papers presented together with 2 invited contributions were carefully reviewed and selected from numerous submissions. The book offers topical sections on location awareness, design support for personal digital assistants, context dependent systems, innovative case studies, usability evaluation in small devices, and novel user interfaces for mobile devices.