Co-processing of Jatropha oil (JO), vacuum residue (VR) and high density polyethylene (HDPE) were investigated to determine the behavior of the individual and blended mixture under atmospheric pressure and thermal heating conditions. A fixed bed tubular batch reactor was used for the experimental study under nitrogen atmosphere. The activity of the four catalysts CAT-A (Ni-Mo/SiAl), CAT-R (ZSM-5 + SiAl), CAT-Z (ZSM-5) and FCC catalyst CAT-N on the co-cracking of binary and ternary mixture has been studied. CAT-R was the best catalyst used for JO + HDPE co-cracking as it leads to the formation of 45%, gasoline range hydrocarbons (C-7-C-11) and 49% diesel range hydrocarbons in the cracked liquid. CAT-Z was the best catalyst for VR + HDPE co-cracking as it lead to the formation of 33% olefins which were absent in the thermally cracked liquid. In case of JO + VR co-cracking CAT-Z was found to show increase in the liquid yield and it also lead to the formation of 37% gasoline range hydrocarbons and 35% diesel range hydrocarbons. It was also observed that the use of catalyst had a positive effect on the pH content of the catalytically cracked liquid products. (C) 2014 Elsevier Ltd. All rights reserved.