The pyrolysis of pistacia, khinjuk seed was investigated with the aim to study the product distribution and their chemical compositions and to identify optimum process conditions for maximizing the bio-oil yield. Fast and catalytic pyrolysis of biomass sample with two selected commercial catalyst, namely BP 3189 and Criterion-424 have been conducted in a well-swept resistively heated fixed bed reactor under nitrogen atmosphere. The maximum bio-oil yield of 66.5% with the use of Criterion-424 and 69.2% with the use of BP 3189 were obtained at the catalytic pyrolysis conditions, while it was only 57.6% without catalyst. The bio-oils were investigated, using chromatographic and spectroscopic techniques. (c) 2006 Elsevier Ltd. All rights reserved.