On behalf of the Program Committee, it is our pleasure to present the p- ceedings of the 13th International Symposium on Recent Advances in Intrusion Detection Systems (RAID 2010), which took place in Ottawa, Ontario, Canada, during September 15-17, 2010. As in the past, the symposium brought together leading researchers and practitioners from academia, government, and industry to discuss intrusion detection research and practice. There were eight technical sessionspresentingfullresearchpapersonnetworkprotection, highperformance, malwaredetectionanddefense(2 sessions), evaluation, forensics, anomalydet- tion and access protection, and Web security. Furthermore, there was a poster session presenting emerging research areas and case studies. The RAID 2010 Program Committee received 102 full-paper submissions from all over the world. All submissions were carefully reviewed by independent reviewers on the basis of technical quality, topic, space, and overallbalance. The?naldecisiontookplaceataProgramCommitteemeetingheldduringMay19-20 inOakland, California, where24paperswereeventuallyselectedforpresentation at the conference and publication in the proceedings. As a continued feature, the symposium later also accepted 15 poster presentations reporting early-stage research, demonstrationof applications, orcasestudies. The authorsof accepted posters were also o?ered the opportunity to have an extended abstract of their work included in the proceedings.