The article contains a short description of the integrated on-line radiological monitoring system, which is part of the Aerosol Sampling Stations (ASS-500) and the Permanent Monitoring Stations (PMS) network in Poland. The integrated system has been designed by the Central Laboratory for Radiological Protection and was implemented in Poland in 2000. It allows prompt detection of the presence of artificial radionuclides in the ground-level atmosphere by means of continuous monitoring of the radioactivity collected on a filter.