MDBAS -- a prototype of a multidatabase management system based on mobile agents. Mobile agent technology brings new possibilities in developing distributed applications. We used mobile agents for building a prototype of a multidatabase management system called MDBAS. The system integrates a set of autonomous databases distributed over a network, enables users to create a global database scheme, and manages transparent distributed execution of users’ requests and procedures including distributed transactions. Developing the system, we have emphasized easy and flexible administration together with efficient execution. We have implemented a dynamic optimization algorithm for distributed query processing. Additionally, a unique feature of MDBAS is the capability to transparently manage mobile execution of database procedures. Technically, our solution is based on Java-based mobile agents that exploit JDBC API for access to underlying databases. In this paper, we present the architecture of MDBAS, glance at the implementation and its difficulties, and discuss design and implementation alternatives.