Polyethylene nano-composites, with different loading of Silicon Nitride (SiN) (0, 0.5, 1.6 and 5.6 wt%) as filler were prepared by polymerization of ethylene, using zirconocene as catalyst. Experimental results showed that activity of zirconocene catalyst activity was higher for the composites having filler loading of 0.5 wt%. The thermal studies using differential scanning calorimeter (DSC) and thermo-gravimetric analysis (TGA) indicated that crystallinity & thermal stability was also influenced with the variation of filler loading. Combustibility studies using Micro-calorimeter showed that increase in the filler loading will decrease the combustibility of polyethylene nano-composites. Wide angle X-ray diffraction (WAXD) results indicated a decrease in the percentage of crystallinity with increase in filler wt%. Scanning electron microscopy (SEM) images revealed that morphology of the composites having 0.5 and 1.6 wt% of SiN are more fibrous when compared to control and composites having 5.6 wt% filler loading. (C) 2013 Society of Plastics Engineers