Abstract: Colonization by the fungal pathogen Candida albicans varies significantly dependent upon the pH and availability of oxygen. Because of our interest in extracellular molecules as potential quorum sensing molecules, we examined the physiological conditions which regulate the production of the aromatic alcohols, i.e. phenethyl alcohol, tyrosol, and tryptophol. The production of these fusel oils has been well studied in Saccharomyces cerevisiae. Our data shows that aromatic alcohol yields for C. albicans are determined by growth conditions. These conditions include the availability of aromatic amino acids, pH, oxygen levels, and ammonium salts. For example, for wild type C. albicans tyrosol production varied 16-fold merely by including tyrosine or ammonium salts in the growth medium. Aromatic alcohol production also depends on the transcription regulator Aro80p. Our results are consistent with aromatic alcohol production via the fusel oil pathway: aromatic transaminases (ARO8 and ARO9), aromatic decarboxylase (ARO10), and alcohol dehydrogenase (ADH). Expression of ARO8, ARO9 and ARO10 is also pH dependent. ARO8 and ARO9 were alkaline up regulated while ARO10 was alkaline down regulated. The alkaline dependent change in expression of ARO8 was Rim101-independent while expression of ARO9 was Rim101-dependent.