Particulate matter (PM) emissions from open beef cattle feedlots can reduce visibility and have negative health implications for animals, workers, and neighbors. As more stringent air quality standards are developed, there is a need to characterize and control PM emission from beef cattle feedlots. This research was conducted to monitor concentrations of PM10 (particulate matter with aerodynamic equivalent diameter of 10 μm or less) upwind and downwind of a commercial cattle feedlot in Kansas and to compare measurement of PM10 with different samplers under field conditions. A 30,000 head commercial cattle feedlot was instrumented with one Tapered Element Oscillating Microbalance™ (TEOM) along its upwind, or southern, perimeter and one TEOM along its downwind, or northern perimeter. Both TEOMs were configured to continuously monitor PM10 concentrations. Results from the continuous monitoring from April to August 2006 indicated net PM10 mass concentration ranging from 102 to 234 μ g/m3 (20 min averaging time). In addition to the continuous monitoring, one-day field intensive sampling campaigns were conducted in which high-volume and low-volume PM 10 samplers were collocated with the TEOM samplers and were used to measure the time-averaged PM10 concentrations upwind and downwind of the feedlot. Comparison of the samplers indicated that the measured PM 10 mass concentrations were highest with the TEOM PM10 monitors and lowest with the low-volume PM10 samplers.