The antifungal properties of essential oils of Origanum minutiflorum (native to Turkey), O. onites, Thymbra spicata and Satureja cuneifolia were tested against six Rhizoctonia solani isolates obtained from infected seedlings from various forest nurseries in Turkey. Of the two methods to test the essential oils, the volatile assay was slightly more effective than the contact assay. While all Rhizoctonia isolates were strongly affected (> 84.7) in the contact assay, the fungal isolates were completely inhibited by all the essential oils in the volatile assay. R. solani isolate Rs6 was the most sensitive, being suppressed by O. minutiflorum (100%), S. cuneifolia (100%) and T spicata (99.6%). R. solani isolate Rs3 was also strongly inhibited by O. onites (99.1%).