The melt fracture behavior of several commercial polylactides (PLAs) and poly(epsilon-caprolactone) (PCL) is investigated. PLAs and PCL with molecular weights greater than a certain value were found to exhibit melt fracture phenomena in capillary extrusion, which manifests itself as distortions on their surface once the extrusion rate exceeds a critical value. It was found that the addition of a small amount of PCL (typically 0.5 wt %) into the PLA and vice versa is effective in eliminating and delaying the onset of melt fracture to higher shear rates in the capillary extrusion of PLA and PCL, respectively. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013