Telecommunications networks are evolving globally to keep pace with rapid technological, regulatory and market changes. This is particularly evident in the introduction of intelligent network (IN) capabilities by network providers around the world. These IN capabilities will augment the network "intelligence" via the common channel signaling network and distributed service control points allowing users to gain access to advanced communications services. In this paper, we present the results of our research in the area of intelligent multimedia services. One of the main results has been the design of novel multimedia services operating over different network platforms. One of the new services being designed is an intelligent multimedia gateway, providing interconnectivity between the public service telephone network and the Internet. The design of this service has proved useful in gaining insight into the way novel intelligent multimedia services across network platforms will benefit from the use of IN technology. A performance evaluation of the service has also proved valuable to identify the major system and traffic parameters to consider when designing and deploying IN multimedia services across multiple networks. © 1997 Elsevier Science B.V.