The upgrading of a bio-oil using a fixed bed micro-reactor operating at 1 atm, 3.6 WHSV and 330-410 degrees C over various catalysts is reported. The catalysts used were HZSM-5, silicalite, H-mordenite, H-Y and silica-alumina, The yield of hydrocarbons as well as the extent of deoxygenation, coke formation and conversion of the non-volatile portion of the bio-oil were used as measures of catalyst performance. The maximum hydrocarbon yield when HZSM-5 was used occurred at 370 degrees C and was 39.3 wt% of the bio-oil. For the other catalysts, the hydrocarbon yields increased with temperature and were up to 22.1wt% for silicalite; 27.5wt% for H-mordenite; 21.0wt% for H-Y; and 26.2wt% for silica-alumina at 410 degrees C. The hydrocarbon selectivity with HZSM-5 and silicalite catalysts was mostly for gasoline range hydrocarbons (C-6 to C-12) and for H-mordenite and H-Y for kerosene range hydrocarbons (C, to C,,). The hydrocarbon fraction obtained with silica-alumina did not produce any defined distribution. The pore size, catalyst acidity and catalyst shape selectively affected the product distribution. The overall performance followed the order: HZSM-5 > H-mordenite > H/Y, silica-alumina, silicalite.