This book constitutes the thoroughly refereed post-proceedings of the 8th International Workshop on Runtime Verification, RV 2008, held in Budapest, Hungary, in March 2008 as satellite event of ETAPS 2008. The 9 revised full papers presented together with 2 invited papers were carefully selected from 27 initial submissions. The subject covers several technical fields such as runtime verification, runtime checking, runtime monitoring, and security and safety matters.