This set of proceedings contains the most significant papers presented at the third IFAC Workshop on Artificial Intelligence in Real-time Control, which was held from September 23-25, 1991 in the USA. In this workshop, although there were still some "exotic" applications, a more practical view of the applications and limitations of current AI technology dominated the participants' discussions. With its resultant focus on reliability and safety considerations, the workshop posed as many questions as it answered. It provides an excellent mirror of the current state-of-the-art which these proceedings are intended to illustrate.