A baffle-type pre-separator was installed prior to both a 2D-2D and a 1D-3D cyclone handling the exhaust from a seed cotton unloader separator. The pre-separator reduced the total dust concentration in the exhaust by 15 to 17% and the combined collection efficiency was 0.5 to 0.8% higher than for the cyclone alone. The combined efficiency for the pre-separator and the 1D-3D cyclone was about 2.1% higher than that for the pre-separator and the 2D-2D cyclone. The pre-separator did not improve the collection efficiency for either cyclone on particles with an aerodynamic diameter of 10 microns or less (PM10). Thus, the pre-separator improved the total collection efficiency but did not improve the collection efficiency for PM10 particles.