The ultra-high molecular weight polyethylene (UHMWPE) has many excellent properties as high impact resistance, low abrasion and low coefficient of friction. However, it has a high viscosity which makes its processing by conventional methods impracticable. To overcome this limitation, polyethylene blends of ultra high molecular weight with other conventional thermoplastics are being studied, aiming to give part of the good properties of UHMWPE but keeping the good processability. The purpose of this study was to investigate the effect of the incorporation of milled reactor powder of UHMWPE in the abrasion resistance of high density polyethylene (HDPE). UHMWPE was processed by high energy ball milling in an Attritor mill. After that, blends of HDPE with 5 and 15 wt. % of milled and non-milled UHMWPE were prepared in a single screw extruder. The specimens were then prepared by injection molding. The samples were characterized by optical microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and abrasion resistance. Preliminary results have shown that blends of HDPE with milled UHMWPE present better dispersion of the UHMWPE than blends of HDPE with non-milled UHMWPE. Abrasion tests are in progress.