In Poland, regional spatial information systems have spontaneously developed since a dozen years or so and their primary task is to support the activities of marshal s offices in individual voivodships. The development of these systems is presently shaped by the INSPIRE Directive, its transposition in the form of the Act on spatial information infrastructure and by secondary legislation related to spatial information infrastructure and interoperability framework. In the paper, consequences of legal regulations in force are exposed drawing attention to the necessity of understanding the system as a kind of basis of a regional spatial information system. Broadly understood objectives of the system are specified drawing attention to its integration role and data sources. Legal conditions are characterized and features of target system are presented. At the end, conclusions are provided confirming the need for further development of regional spatial information systems in accordance with binding provisions of law and recommending to undertake properly organized inter-regional cooperation in this field.