The Bureau of Mines turbomill is being evaluated for the production of ultrafine, high-purity, ceramic powders, which could contribute to improve performance of structural materials fabricated for use in severe conditions of temperature, pressure, and environment. The materials studied were alpha-silicon carbide (alpha-SiC), silicon nitride (Si3N4), titanium diboride (TiB2), quartz (SiO2), alumina (Al2O3), and zirconia (ZrO2). Ultrafine alpha-SiC powders with an average diameter of 1.31 microm (51 pct <1 microm) were produced in 1 h in the Bureau's all-polymer turbomill. A sodium lignosulfonate was found to be the best dispersant for SiC powders. Si3N4 powders were prepared from two different starting materials, each with a diameter of 55 microm. Milled powders had average particle sizes of 2.96 microm (20 pct <1 microm) after 1 h in the one case, and 2.09 microm (51 pct <1 microm) after 2 h in the other. TiB2, with an average initial diameter of 35 microm was reduced to 5.52 microm (2 pct <1 microm) in 1 h. SiO2, ZrO2, and Al2O3 (starting materials with average diameters of 30.52, 20.11 and 101.74 microm) were ground to 3.44 microm (12 pct <1 microm), 3.09 microm (15 pct <1 microm), and 2.69 microm (28 pct <1 microm), respectively, in 1 h. Contamination of the powders produced in the turbomill was negligible, which is advantageous for high-temperature applications where purity is a primary concern.