Thermal, electrical, as well as mechanical behavior of blends of polyamide 6/polystyrene (PA6/PS) (50/50 wt/wt%) loaded with different concentrations of lead dioxide (PbO2) were investigated for X-ray shielding. Thermal stability and hardness (shore D) of these composites are studied. Addition of PbO2 decreases the thermal stability of the prepared composites. Stability of thermal properties confirmed by determining the activation energy for the thermal decomposition of unfilled PA6/PS and filled composites according to the Horowitz and Metzger method. Dielectric properties of bulk PbO2 have been investigated as a function of frequency and temperature in the frequency range from 40 Hz to 5 × 106 Hz and in the temperature range from 293 K to 423 K. The characterization of the prepared composites is done using scanning electron microscope. With PbO2-loaded PA6/PS blends composites, the dielectric properties were significantly influenced by γ-irradiation effects that ε′ and [Formula: see text] values increase with radiation dose up to 100 kGy for samples loaded with PbO2. Linear attenuation coefficient μ and half-value layer (HVL) of all composites strongly depend on the concentration of the filler used and the applied voltage of X-ray machine. HVL of the obtained composites that loaded with 100 wt/wt% of PbO2 nearly 3 mm can be used as X-ray tube housing, equipment housings and castings, electronic devices protection, and so on.