Software plays a key role in high-risk systems, i.e., safety and security-critical systems. Several certification standards and guidelines, e.g., in the defense, transportation (aviation, automotive, rail), and healthcare domains, now recommend and/or mandate the development of assurance cases for software-intensive systems. As such, there is a need to understand and evaluate (a) the application of assurance cases to software, and (b) the relationship between the development and assessment of assurance cases, and software engineering concepts, processes and techniques. The ICSE 2013 Workshop on Assurance Cases for Software-intensive Systems (ASSURE) aims to provide an international forum for high-quality contributions (research, practice, and position papers) on the application of assurance case principles and techniques for software assurance, and on the treatment of assurance cases as artifacts to which the full range of software engineering techniques can be applied.