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 theme of the ICSE 2013 Workshop on Assurance Cases for Software-intensive Systems (ASSURE) is the relation between assurance cases and software. Not only do we want to apply assurance case principles and techniques to software assurance, but also we want to treat assurance cases as artifacts to which the full range of software engineering techniques can be applied.