Ambient Intelligence (AmI) systems are collections of interconnected services that use heterogeneous devices to integrate smoothly in the everyday environment of their users. Engineering these systems is a challenging task, where designers need to deal with issues such as information management, users' profiles and activities, privacy, distribution, or continuous availability. The application of the multi-agent paradigm to develop these systems has been one of the most active lines of research in the area. Its abstractions of intentional and social agents are useful to analyze AmI systems with an integrated view of people and the services working for them. Moreover, this paradigm already offers solutions to deal with many of the key aspects of AmI. This special issue highlights some state-of-the-art works in this line. It presents contributions regarding agent-oriented architectures and development processes for AmI, as well as illustrative industrial systems built under this approach.