The thermal and catalytic upgrading of bio-oil to liquid fuels was studied at atmospheric pressure in a dual reactor system over HZSM-5, silica-alumina and a mixed catalyst containing HZSM-5 and silica-alumina. This bio-oil was produced by the rapid thermal processing of the maple wood. In this work, the intent was to improve the catalyst life. Therefore, the first reactor containing no catalyst facilitated thermal cracking Of bio-oil whereas the second reactor containing desired catalyst upgraded the thermally cracked products. The effects of process variables such as reaction temperature (350 degrees C to 410 degrees C), space velocity (1.8 to 7.2 h(-1)) and catalyst type on the amounts and quality of organic liquid product (OLP) were investigated. In the case of HZSM-5 catalyst, the yield of OLP was maximum at 27.2 wt% whereas the selectivity for aromatic hydrocarbons was maximum at 83 wt%. The selectivities towards aromatics and aliphatic hydrocarbons were highest for mixed and silica-alumina catalysts, respectively, in all catalyst cases, maximum OLP was produced at an optimum reaction temperature of 370 degrees C in both reactors, and at higher space velocity. The gaseous product consisted of CO and CO2, and C-1-C-6 hydrocarbons, which amounted to about 20 to 30 wt% of bio-oil. The catalysts were deactivated due to coking and were regenerated to achieve their original activity.