This work investigates the effect of carbon dioxide as cosolvent on the production of fatty acid ethyl esters from soybean oil transesterification in supercritical ethanol in a continuous catalyst-free process. The experiments were performed in a tubular reactor in the temperature range of 573-623 K, from 7.5 to 20 MPa, with an oil to ethanol molar ratio ranging from 1: 10 to 1:40 and cosolvent to substrates mass ratio from 0: 1 to 0.5: 1. Results showed that the yield of ethyl esters decreased with increasing addition of carbon dioxide to the system. The reaction conversion was noticed to decrease at lower substrates flow-rates due to products decomposition. Considerable reaction yields were achieved at 623 K, 10 MPa, oil to ethanol molar ratio of 1:40 and using a CO2 to substrate mass ratio of 0.05: 1. It is shown that the use of a tubular reactor with smaller inner diameter can provide high reaction conversions in short residence times, thus offering a promising route for the investigation of biodiesel production.