Bytecode, such as produced by e.g. Java and .NET compilers, has become an important topic of interest, both for industry and academia. The industrial interest stems from the fact that bytecode is typically used for Internet and mobile devices (smart-cards, phones, etc.) applications, where security is a major issue. Moreover, bytecode is device-independent and allows dynamic loading of classes, which provides an extra challenge for the application of formal methods. In addition, the unstructuredness of the code and the pervasive presence of the operand stack also provide extra challenges for the analysis of bytecode. This workshop will focus on theoretical and practical aspects of semantics, verification, analysis, certification and transformation of bytecode.