Flaxseed oil is the main component of the flaxseed and has many beneficial functions to human health. In this paper, the ultrasound-assisted extraction of oil from flaxseed is reported. The effects of some operating parameters such as ultrasonic power, extraction time, extraction temperature and solvent to solid ratio on the yield of flaxseed oil have been investigated and some of the results have been compared with that of conventional method. It has been found that ultrasound-assisted extraction requires a shorter extraction time and a reduced solvent consumption. The yield of flaxseed oil has been found to increase with the increase of the ultrasonic power and to decrease as the temperature is increased. Scanning electronic microscopy analysis was carried out on the flaxseed powder after the extraction. The images are powerful evidences to show the effect of ultrasound. The fatty acid compositions of the oils extracted by the ultrasound-assisted method and the conventional method have been analyzed using gas chromatography. It has been shown that the compositions of the flaxseed oils were not affected significantly by the application of ultrasound (p>0.05). The ultrasound-assisted extraction may be an effective method for lipid production.