Abstract. We present a Context-aware Component based on agents that enables developers to build Ambient Intelligence (AmI) Systems for supporting the independent living of elders. This component uses the ELDeR ontology that we propose to model the context information inherent to the elder’s daily activities and that enables agents to infer risks. Our aim is to provide an ontology flexible enough to easily enable developers to change the contextual conditions for inferring risks in order to respond to a different scenario. In this paper, we describe the functionality of the activity-aware component and the ELDeR ontology and illustrate their use by presenting the design of an application