The pyrolysis of palm shell was performed in a batch conical spouted bed to examine the effects of pyrolysis temperature and time, particle size, and static bed height on the product yields and properties. The optimal pyrolysis condition derived from the batch operation, which produced maximum liquid product yield, was selected for the pyrolysis tests in a continuous mode from which only the effect of pyrolysis temperature was studied. It was found that pyrolysis temperature and time showed a strong effect on the pyrolysis product yields, while particle size and static bed height showed almost no significant effect. For the continuous spouted bed operation, the maximum liquid yield of 65 wt% was obtained under the test condition. With regard to the pyrolysis products, the bio-oil obtained is probably less attractive to use as a direct fuel, due to its high water content, low calorific value and high acidity. The derived solid product gave a calorific value of 31 MJ/kg and a BET surface area of 200-220 m(2)/g. Carbon monoxide and carbon dioxide were the dominant components in the gas product. Batch and continuous operations yielded similar char properties and gas compositions.