This book constitutes the refereed proceedings of the 10th International SPIN workshop on Model Checking of Software, SPIN 2003, held in portland, OR, USA in May 2003 as an ICSE 2003 satellite workshop.The 14 revised full papers and 3 revised tool papers presented were carefully reviewed and selected from 30 submissions. The book presents state-of-the-art results on the analysis and verification of distributed software systems using the SPIN model checker as one of the most powerful and widely applied systems.