The effect of different oil levels of myrtle (Myrtus communis L), laurel (Laurus nobilis L.), pickling herb (Echinophora tenuifolia L. subsp. sibthorpiana (Guss.) tutin), thyme (Thymbra spicata L.) and savory (Satureja hortensis L.) which grow wild in Turkey were investigated on the mycelial growth of Agaricus campestris in vitro. The results showed that all concentrations of thyme ans savory showed a strong inhibitory effect on mycelial growth. The levels of 5μl of pickling herb, 5 μl and 15 μl of laurel, and 5 μl level of myrtle oils, respectively, showed inhibitory effect according to until 26, 11, 18 and 4 days of incubation while 25 μl levels of all herb oils showed a stronger inhibitory effect. As a result, the effectivenes of the inhibitors followed the sequence: thyme=savory > pickiling herb > myrtle > laurel herb. © 2005 Taylor & Francis Group, LLC.