The mechanisms of radionuclide behavior in different environmental objects have been identified and studied. The radiation characteristics of controlled parameters have been shown to be in the range of mean long-term values that are characteristic for the technogenic background of a capital megapolis, they are not greater than those established by the monitoring standards and those required by regulating legislative documents. Areas have been regionalized by the radiation agent and set off as having high levels of natural radionuclides in the soil and high levels of radon in the soil air. It has been shown that, to ensure radiological monitoring under urban conditions, it is most reasonable to have an irregular network considering the concentration of radiation-risk enterprises, as well as urban architectural designs and division of areas by taking into account regional, geomorphological, and radiological factors. Basic trends in improving radioecological monitoring are given.