The focus of this work is a radiatively heated, free-fall, fast pyrolysis reactor. The reactor was designed and constructed for the production of bio-oil from the fast pyrolysis of biomass. A central composite design of experiments was performed to evaluate the novel reactor by varying four operating conditions: reactor temperature, biomass particle size, carrier gas flow rate and biomass feed rate. Maximum bio-oil yields of 72 wt % were achieved at a heater set point temperature of 600 yC, using particle sizes of 300 micron, carrier gas flow rates of 4 sL/min and Red oak biomass feed rates of 1.75 kg/hr. Optimal operating conditions were identified for maximum bio-oil yields at a heater set point temperature of 572 ˚C, feeding 240 micron sized Red oak biomass particles at 2 kg/hr. Carrier gas flow rates were not found to be significant over the 1 - 5 sL/min range tested.