Self-Organization is a key technique to handle the growing complexity of upcoming computing systems. This refers to both hard- and software. Distributed systems running hundreds of tasks on dozens of processors, each equipped with a multiple cores, require self-organization principles to ensure efficient and reliable operation. Therefore, substantial research has been done in the last years to address the so-called Self-X features like self-configuration, self-optimization, self-adaptation, self-healing, self-protection, etc. Additionally, real-time properties are another key issue in many complex systems (e.g., in the embedded systems area). Combining the flexible and – to some extent - uncertain behavior of self-organizing systems with time-predictability necessary for real-time systems is a grand challenge. Continuing the series of its predecessors, the forth IEEE workshop on Self-Organizing Real-Time Systems (SORT 2013) will be a forum for leading researchers to continue in exchanging ideas, presenting advances in state-of-the-art and brain-storming on promising directions for future research. SORT 2013 will be held in conjunction with the 16th IEEE Int'l Symposium on Object/component/service-oriented Real-time Distributed Computing (ISORC) taking place at Paderborn, Germany. Proceedings will be published by IEEE.