Composites containing various amounts of LLDPE (Linear Low Density Polyethylene) and clay (0, 1, 5, 10, 20 and 30% of clay) were prepared using two different types of clay (Bijoypur white clay and China clay) by extrusion technique followed by compression molding. Tensile strength (TS) & tensile modulus (TM) of pure LLDPE were found to be 9.8 MPa & 175 MPa respectively. For both types of clay TS, Eb% was gradually decreased but TM was gradually increased with increasing the percentage of clay in LLDPE/clay composites. The effects of ionizing (gamma) and non-ionizing (UV) radiations on the mechanical properties of LLDPE/clay composites were studied. The composites irradiated under UV & gamma radiation showed higher TS than that of non-irradiated one. Thermal degradation of the composites was studied at different temperatures. Water uptake of the composites was found negligible.