Most existing wireless sensor network (WSN) installations have in common that they are not considered time-critical. No immediate action has to be undertaken as a response to the received data. However, many emerging WSN applications such as plant automation and control, smart cities or health care applications require immediate and guaranteed actions. In such environments, data has to be transported reliably and in time through the sensor network. In some scenarios, data even has to travel through the sensor network and the Internet to reach the destination. In this situation the overall system spanning the Internet and sensor networks must provide together the required performance characteristics. Due to the lack of appropriate models, components and protocols, it is currently very difficult to construct and operate a WSN with performance guarantees. Thus, the commercial success of wireless sensor networks in many application areas is unsure unless this particular problem is understood and solved. The PWSN workshop aims at bringing together researchers and practitioners designing and deploying sensor networks that have to meet specific performance targets.