This volume contains a number of revised papers that were selected from - pers presented at the last ModelAge workshop held in Certosa di Pertignano (Italy) in 1997, organised by the Institute of Psychology of the Italian CNR (IP-CNR), Division of Arti cial Intelligence, Cognitive Modeling and Inter- tion. The organisation chair was held by Amedeo Cesta. The workshop, and indeed the ModelAge project as a whole, aimed to bring together a number of researchers stemming from di erent disciplines to discuss formal models of agency from di erent perspectives. These disciplines included arti cial intel- gence, software engineering, applied logic, databases, and organisation theory. The e ld of intelligent agents has become an important research area within these disciplines, and in the workshop as in the present volume the concept of agency is thus considered from a multi-disciplinaryperspective. In the introductory chapter of this volume more can be found on the area of intelligent agents as well as on the topic of formal models of these. We f- thermore provide some key references, so that the reader can better appreciate the position of the present volume within the literature on agent technology.