High density polyethylene (HDPE) was drawn at 80-degrees-C with draw ratios from 1 to 3.5. The resistance to slow crack growth was measured on notched tensile specimens under plane strain conditions and over a range of temperatures. The notches were made parallel or perpendicular to the direction of orientation. The failure times for crack growth perpendicular to the orientation direction varied exponentially with the draw ratio, and for crack growth parallel to the orientation direction the time of failure decreased to zero fora draw ratio of about 1.5. The activation energy was 110 kJ mol-1 and was independent of the draw ratio.