Processes are disclosed for oxygen-tailoring polyethylene blow molding resin. Polyethylene resin is conveyed through a feed zone, a melt-mixing zone and a melt zone, wherein the temperature of the polyethylene resin is from about 216.degree. C. to about 260.degree. C. in the melt zone. The resin is contacted with oxygen in an amount of at least about 20 parts by weight oxygen per million parts by weight resin. The oxygen-treated resin can be used to make polyethylene blow molded articles having improved melt strength, processability, and die swell.