The pyrolysis of biomass is a very old energy technology that is becoming interesting again among various systems for the energetic utilization of biomass. In the present work, pyrolysis of neem seeds (Azadirachta Indica) was investigated with an aim to study the physical and chemical characteristics of the bio-fuel produced and to determine its feasibility as a commercial fuel. Thermal pyrolysis of neem seeds was done in a semi-batch reactor at a temperature range of 400-500 degrees C and at a heating rate of 20 degrees C/min. The FTIR analysis of the bio-fuel indicates the functional groups such as alkanes, alkenes, ketones, carboxylic acids and amines. The composition of the liquid product was analyzed using GC-MS and found that the main constituents were octadecanenitrile, oleanitrile, 9-octadecenoic acid methyl ester, stearic acid methyl ester. The obtained liquid product can be used as a valuable chemicals feedstock. The physical properties of the bio-fuel obtained were close to that of petroleum fractions. (C) 2012 Elsevier Ltd. All rights reserved.