Enterprise Application Integration (EAI) techniques are today widely adopted to build Enterprise Information Systems. Moreover the increasing reliability of tools and techniques stemming from the "Internet revolution" is rendering ever more convenient to base the development of new applications on Web technology, especially because of the great advantages it affords in terms of scalability and distribution. These two approaches can be used together to build highly integrated and flexible computer systems for powerful Web-based Information Systems (WIS). In the paper we'll present the main approaches in EAI and the issues that need to be tackled in using EAI for building Public Access WIS KEYWORDS Web-based Enterprise Systems, Web-based Information Systems, Enterprise Application Integration (EAI).