A survey of airborne dust concentrations in the non textile cotton industry was conducted. Cotton dust concentrations and size distributions were determined at 92 facilities, including cotton gins, classification offices, cotton seed oil mills, cotton compress/warehouses, and waste utilization facilities. The facilities in five geographical regions of the United States included the lower Southwest, South Central, Southeast, upper Southwest, and the West. Airborne cotton dust concentrations were measured with vertical elutriators. Size distributions were determined with an eight stage cascade impactor. Average dust concentrations were 521 micrograms per cubic meter (microg/m3) for cotton gins, 165microg/m3 for classification offices, 1008microg/m3 for cottonseed oil mills, 229microg/m3 for compress/warehouses, and 1390microg/m3 for waste facilities. Eighty percent of the facilities had mean dust concentrations of 100microg/m3 or less and 54 percent had an average concentration of 500microg/m3 or less. Mass median aerodynamic diameters in the gins, cottonseed mills, and classing offices were 5.3, 4.5, and 4.1 micrometers, respectively. The authors conclude that the results are generally lower than those reported previously. Health hazards associated with cotton dust may not vary directly with the dust concentration. The etiologic agent may vary from one process to another.