This research attempted to demonstrate a simple method to produce high‐grade pyrolysis oil by maximizing the use of biomass wastes. In this study, the results of pyrolysis of palm shell alone are compared with pyrolysis of palm shell/polystyrene mixtures (1:1 weight ratios). Pyrolysis was carried out in a fixed‐bed reactor under the following conditions: a temperature of 500°C, a nitrogen flow rate of 2 L/min, and reaction time of 60 min. The results showed that the final oil yield of palm shell pyrolysis was about 46.13 wt %. By mixing the palm shell with polystyrene, the yield of oil increased to about 61.63%. In these experiments, the high heating value was low (11.94 MJ/kg) for oil from pyrolysis of palm shell. By contrast, the high heating value was a high 38.01 MJ/kg for oil from pyrolysis of material mixtures. In addition, by using this method, more waste matter can be consumed as raw material for pyrolysis oil production, which also benefits waste management and energy security in Malaysia. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1026–1033, 2014