The effect of quinic acid on growth of wild yeasts ( Hansenula anomala , Saccharomyces cerevisiae and Schizosaccharomyces pombe ) and molds ( Aspergillus amstelodami , Botrytis cinerea and Byssochlamys fulva ) was investigated. Quinic acid alone had no antifungal effect on the microbes tested. Generation time of the yeasts remained unaltered in the presence of up to 1% quinic acid, whereas growth of the molds was accelerated. No synergistic effect of quinic acid together with potassium sorbate or sodium benzoate was observed. Quinic acid was antagonistic to the antifungal effects of both potassium sorbate and sodium benzoate on molds. In co-use with sorbate and benzoate, quinic acid shortened the lag phase of the growth of molds. The inhibitory effect of 0.01 to 0.02% sodium benzoate was almost completely eliminated by adding 1% quinic acid.