5th International Workshop on Science Gateways Science gateways are a community-specific set of tools, applications, and data collections that are integrated together via a web portal or a desktop application, providing access to resources and services of distributed computing infrastructures (DCIs). Science gateways offer the potential to open the utilisation of DCIs to wider audiences by providing a customised and easy to use user interface to access large computational and data resources. The complexity of the underlying infrastructure can be completely hidden from the end-users by a suitably tailored interface. As interest in science gateways has accelerated in the past few years, an increasing number of new user communities can utilise grid or cloud computing resources in a convenient manner. The 5th International Workshop on Science Gateways brought together researchers and scientists from different scientific domains, along with science gateways developers, to discuss problems and solutions in the area, to identify new issues, to shape future directions for research, foster the exchange of ideas, standards and common requirements and push towards the wider adoption of science gateways in e-Science. We were specifically happy about the growing interest in the workshop that has resulted in 33 accepted contributions, nearly twice as much as last year. Some of these contributions were lightning talks submitted as abstracts and published on the conference website (http://iwsg2013.org). The other 18 contributions were full papers compiled for this current proceedings. Tamas Kiss, University of Westminster, Editor and Chair of IWSG 2013 For more information please visit the workshop website at http://iwsg2013.org See also proceedings of previous workshops at CEUR: http://ceur-ws.org/Vol-819/ http://ceur-ws.org/Vol-513/