The antifungal activities of four spice decoctions (sage, wild thyme, oregano and savory) which grow wild in Turkey against six moulds (Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseoli, Botrytis cinerea, Rhizoctonia solani, Alternaria solani and Aspergillus parasiticus) were tested for fungistatic and fungicidal activity in vitro. Decoctions were added at 5% and 10% levels to 250 ml culture medium. The results showed that the decoctions investigated varied in their antifungal activity. Sage had weak activity, whilst wild thyme, oregano and savory were active against all moulds tested. All test fungi were completely inhibited by both of the concentrations of wild thyme and the 10% level of oregano decoctions in all the incubation periods. It was concluded that some decoctions may be useful as mould inhibitors at food additive levels.