In the decommissioning of the campus B at VNIINM located in a dense residential area in Moscow special attention was devoted to radiation monitoring. For this, the automated radiation monitoring system (ARMS) and mobile-ARMS were involved, the former during decommissioning and the latter during the most critical work; additional measurements were performed in the ventilation channel over 168 days. ARMS in the automatic mode performed 112,492,800 measurements of the γ-exposure dose rate and 793,152 measurements of the concentration of aerosols containing α- and β-emitting radionuclides; the mobile system performed 17,038,080 and 84,796 measurements, respectively. Radiation monitoring was conducted in the man-made objects at VNIINM and on components of the environment on and off the grounds of the enterprise.