Eight antimicrobial compounds were evaluated for the selective isolation of cotton seedling disease fungi from soil. Potato dextrose agar was used as a basal medium. Three media-. sodium chloride + pentachloronitrobenzene (NaCl-PCNB) (5% + 375 mglL), imazilil (50 mg/L), and thiabendazole + pentachloronitrobenzene (mortect-PCNB) (75 mg/L + 375 mg/L) were selected for soil assay trials. NaCl-PCNB was more effective in isolating Fusarium sp and imazilil medium more efficient in isolating Rhizoctonia solani when compared to standard isolation media for these fungi. Mertect-PCNB selected for Pythium sp but was not as effective as standard media due to inhibitory effects on Pythium growth.