Rio de Janeiro has the second strongest state economic movement in Brazil, as a consequence it has great influence over the Brazilian southeastern region in international trade operations, based on a privileged harbor infrastructure. Over the years, goods and products worth billions of dollars have been imported and exported through harbors located in Rio. A diagnostics of these operations is a necessary tool for the transportation systems planning in the state, as well as the use of information systems to support decision-making, since there`s a large amount of data to be handled and the ensuing complexity of the problem. This dissertation proposes, develops, tests and implements an information system model for storage and analysis of data concerning the international trade operations involving the state of Rio de Janeiro and its outskirts together with a query interface model for computer aided human diagnostics of these operations. This work also includes the use of Geographic Information Systems for visualization of query results and diagnostic assistance. The main result of this work is to make available a useful information systems tool for diagnostics in Logistics. Among various sample conclusions of a prototypical use of the tool with data in the range 1999- 2002 were: the confirmation of the need for a surrounding expressway, that the main foreign client is the US with 18% of the total and that the majority of the products belong to the Oil industry.