The effects of catalyst acidity and the restricted reaction volume afforded by the HZSM-5 zeolite structure on the volatile cracking products derived from poly(ethylene) are investigated. The effectiveness of silica-alumina, HZSM-5, and sulfated zirconia acid catalysts for poly(ethylene) cracking are compared. When high catalyst to polymer ratios are employed and volatile products are rapidly removed during cracking, the most abundant volatile products generated by poly(ethylene) cracking are propene and isoalkenes. The relative amount of propene produced and the temperatures corresponding to the maximum rate of volatile hydrocarbon production are found to be related to catalyst acidity. The restricted volume inside HZSM-5 channels facilitates oligomerization and the production of small alkyl aromatics.