The thesis is focused on radiological and chemical weapons in the context of their use in terrorist attacks against the civilian population in relation to rescue and clean up operations of the Integrated Rescue System (IRS) of the Czech Republic. The objective of the thesis is to specify the terms of radiological and chemical weapons, to assess potential negative consequences of their use with the emphasis on the threat to life and health of the population, to evaluate the economic impact on society and to compare the IRS activities during the immediate intervention carried out after a terrorist attack. The topic is dealt with based on the research and the analysis of rules of law in force regulating activities of the IRS components in these major incidents and also of documents of the IAEA (International Atomic Energy Agency) and other works focused on the misuse of radioactive and chemical agents in terrorist attacks. Severity and complexity of the issue is illustrated by information given on the radiological accident in Goiana in Brazil, sarin attacks of the Japanese sect Óm šinrikjó and consequences of the model example of the use of radionuclide 137Cs. In the thesis the current methodology on which the IRS components operate in such emergencies is analyzed, and some aspects that are subject of the set of type activities, worked out by the Civil Emergency Planning Committee and DG Fire Rescue Service of the CR, which may become weak points during a real action of the IRS, are pointed out. One of major issues analyzed in this study is comparison of radiological and chemical attacks with the focus on the initial phase of the intervention of the IRS components. Presentation of differences in individual activities of the IRS components in such interventions can contribute significantly to understanding and subsequently managing the activities carried out by the IRS components in these major incidents.