Novel interactive systems often combine digital representations with physical, real-world artifacts. Such intelligent and tangible user interfaces (I&T UI) offer new ways for users to collaborate with others, manipulate data, to interact with humans and computers. It is argued that ‘natural collaboration’ is supported when people can reach out and touch with their fingers or assemble around a table. Other participants and their physical chains of actions support coordination, while material artifacts or a tangible tabletop act as mediators. The use of gestures, interventions with tokens, modifications and content manipulation extend the possibilities of collaboration and co-construction. Participants do not just have to discuss in a confrontational way face-to-face. IUI employs intelligent processing and interfaces that leverage artificial intelligence techniques. The artifacts take a key role in intelligent and tangible user interfaces and materialize the possible modes of collaboration and interaction. Therefore their collaborative aspects are central to participants exchange and interactions with each other and a UI, e.g., the ColorTable – a tangible tabletop supporting negotiation process to collaboratively plan future urban scenarios in participatory settings. The aims of this workshop are to further explore potentials of collaborating with and supported by intelligent and tangibles – their integration into the interaction, their material features and how these contribute to participants’ collaboration and modes of interaction. Therefore we look forward to further learn and understand the various modes of collaboration offered by UIs and exchange our experiences throughout fieldwork, design cases and research projects. Beyond that we want to encourage the discourse about the aspects and complexity of collaborative work and design with intelligent and tangible interfaces in theory and practice. The workshop is planned for a full day, starting with a keynote and includes demonstrations. The combination of practical experiences and theoretical concepts will be a good basis for research exchange and support researchers to further explore and develop natural collaboration possibilities and cooperative concepts mediated by UIs. The workshop works will be included in the CTS proceedings.