In order to destroy pathogenic microorganisms and to avoid infections it is necessary to disinfect drinking water. Due to its high effectiveness and easy handling chlorine dioxide is a very common disinfectant, While it has one distinctive disadvantage. Chlorine dioxide is a strongly oxidizing agent, which may cause serious damage to the pipes due to chemical and physical aging. Since a lifetime of 50 years is required, this point must not be underestimated in the specific case of Polyethylene. In the present work three types of PE-RT (Polyethylene of Raised Temperature resistance) were exposed to chlorine dioxide at three different temperatures for up to 672 h. After exposure the specimens were tested by means of conventional test methods and unexposed specimens were used for references. The aim of this work was a comprehensive characterization of the chemical and physical aging behavior, the mechanical properties and the crack-resistance of PE-RT under the influence of chlorine dioxide. The main attention was paid on the influence of the exposure time and the exposure temperature. In order to gain significant results conventional test methods like tensile tests (mechanical characteristics), dynamic mechanical analysis (thermo mechanical characteristics), differential scanning calorimetry (crystallinity and oxidation induction time) and infrared spectroscopy (carbonyl index) were performed. The crack resistance of the materials was investigated by cyclic Crack Round Bar (CRB) tests on exposed specimen in air and on unexposed specimens in a special medium test cell. At an exposure temperature of 23 °C no distinctive influence of chlorine dioxide on Polyethylene was detectable during the investigated exposure time. In comparison to that at higher temperatures chemical and physical aging of the materials were proven by conventional test methods. The cyclic CRB-tests did not show any significant results without any difference between the references, the exposed specimens and the tests within the medium test cell.