Flash pyrolysis oil from an ENSYN RTP pilot plant was upgraded in a continuous bench scale unit with commercial CoMo and NiMo catalysts in anticipation of scaling up the process. Large amounts of product were produced in a pilot plant For use in an extended analytical characterisation programme. In bench-scale experiments, high deoxygenation rates of 88-99.9% were achieved. Low liquid and high water yields were obtained. The fractionated products of the production run did not fulfil the requirements for direct use as gasoline and diesel. The process is restricted by several operational problems such as rapid catalyst deactivation, coking and plugging. Due to high feedstock and hydrogen addition costs, pyrolysis upgraded oil by the process tested is significantly more expensive than petroleum-derived oil at present oil prices.