The slip behavior of several high-density polyethylenes (HDPEs) is studied as a function of molecular weight (M-w) and its distribution for broad molecular weight distribution metallocene and Ziegler-Natta catalyst resins. It is found that slip depends strongly on M-w and its distribution. First, the slip velocity increases with decrease of molecular weight, which is expected to decay to zero as the M-w approaches a value with characteristic molecular dimension similar to surface asperities. For HDPEs that exhibit stick-slip transition, the slip velocity has been found to increase with increase of polydispersity. The opposite dependence is shown for HDPEs of wider molecular weight distribution that do not exhibit stick-slip transition. A criterion is also discussed as to the occurrence or not of the stick-slip transition which is found to depend strongly on M-w and its distribution. (C) 2013 The Society of Rheology. [http://dx.doi.org/10.1122/1.4801758]