During the 1982 growing season, replicated field plots were established in cotton fields known to have Phymatotrichum root rot, in order to evaluate propiconazol for disease control. Foliar sprays of propiconazol at 0.5 lbs a.i./A and side-dress applications of granules at 1.0 and 2.0 lbs a.i./A produced significant reductions in percent disease and increases in yield in upland cotton (DPL-55), but not in Pima cotton (Pima S-5). This is the first report of a systemic fungicide applied to the foliage of cotton to control Phymatotrichum root rot. Injection of propiconazol with anhydrous ammonia as a carrier, at rates similar to the granule applications, did not result in significant disease reductions or yield increases.