Extensive concentration has been given to the development of renewable energy due to imminent demand of fossil fuels and environmental concerns over global warming. Biomass materials are used since millennia for meeting myriad human needs including energy. In this study, the pyrolysis characteristics of cotton shell were investigated to evaluate their potential use as source of bio-oil. Flash pyrolysis of the cotton shell was carried out on an electrically heated fluidized bed reactor. The effects of operating parameters such as temperature, particle size and sweep gas flow rate were investigated. In this study, the maximum yield of pyrolysis bio-oil 51.25 wt% can be obtained under the operation temperature of 450 °C, 1 mm particle size at sweep gas flow rate of 1.75 m3/h. The liquid product was analyzed for physical, elemental and chemical composition using Fourier transform infra-red (FTIR) spectroscopy, gas chromatography (GC) and 1H NMR spectroscopy.