Protection engineers use data from a range of monitoring devices to perform post-fault disturbance diagnosis. In the past, heterogeneous intelligent systems have been developed to interpret the data and provide information to engineers to assist with the disturbance diagnosis task. The majority of these systems remain standalone due to the problems associated with systems integration. This paper proposes the use of multiagent systems for providing a flexible and scalable alternative to existing integration approaches. A novel multiagent system (MAS) has been developed entitled protection engineering diagnostic agents (PEDA) which integrates a legacy SCADA interpretation system with new systems for digital fault recorder (DFR) record interpretation and for enhancing fault record retrieval from remote DFR's. The use of MAS technology provides a flexible and scalable architecture open to the introduction of new data interpretation systems. The paper discusses the benefits of a multiagent approach and the design and implementation of PEDA.