Technical Abstract: Cyclones are commonly used in the processing industry as primary particulate emissions abatement devices. A study was conducted to evaluate the effectiveness of one, two, three, or four 1D3D cyclones, in series, on airstreams heavily loaded (236 g/m3) with fine particulate (mass median diameter <10 µm). The overall efficiency of a single cyclone (91%) was significantly lower than that of the series cyclone configurations (98%). Also, a single cyclone was consistently less efficient (91%) and had a higher static pressure loss (1356 Pa[5.4 in. w.g.]) than the No. 1 cyclone in the series configurations (94% efficiency and 881 Pa [3.5 in. w.g.] static pressure loss). Particle size distributions showed that there was a significant shift toward smaller sized particles in dust captured by the cyclones (8.78 to 1.86 µm) and the dust emitted by the cyclones (3.23 to 1.52 µm) as the number of series cyclones increased from one to four. A secondary cyclone increased overall efficiency significantly with an insignificant rise in static pressure loss, while additional cyclones raised efficiency only about 1% more and increased pressure losses by 150%.