The First International ICST Conference on Sensor Systems and Software (S-cube 2009) was held during 7–8 September in Pisa, Italy. This new international conference was dedicated to addressing the research challenges facing system dev- opment and software support for systems based on wireless sensor networks (WSNs) that have the potential to impact society in many ways. Currently, wireless sensor networks introduce innovative and interesting application scenarios that may support a large amount of different applications including environmental monitoring, disaster prevention, building automation, object tracking, nuclear reactor control, fire det- tion, agriculture, healthcare, and traffic monitoring. The widespread acceptance of these new services can be improved by the definition of frameworks and architectures that have the potential to radically simplify software development for wireless sensor network-based applications. The aim of these new architectures is to support flexible, scalable programming of applications based on adaptive middleware. As a con- quence, WSNs require novel programming paradigms and technologies. Moreover, the design of new complex systems, characterized by the interaction of different and heterogeneous resources, will allow the development of innovative applications that meet high-performance goals. Hence, WSNs require contributions from many fields such as embedded systems, distributed systems, data management, system security and applications. The conference places emphasis on layers well above the traditional MAC and routing and transport layer protocols.