SUMMARYAmino acid uptake was followed during pHregulated dimorphism of Candida albicans. It was observed that transport activities of various amino acids differed with the morphological phenotype. The uptake rates of L-alanine, L-phenylalanine and of L-lysine were lower and those of Lmethionine were higher in elongated hypha (germ tube), while the rates of glycine, L-glutamic acid and L proline were similar in bud and hyphal phenotypes. Minimum threshold of amino acids transport activity is required at the time of phenotypic commitment in a diverging population of Candida albicans.