Orthovanadate-resistant mutants of diploid yeast Candida albicans were isolated by using two step mutational process. Such mutants had altered plasma membrane H(+)-ATPase activity. Based on the levels of PM-ATPase activity, these mutants could be grouped into two categories; one group included those mutants which did not exhibit reduction in PM-ATPase activity while the other displayed a reduction of upto 40% in enzyme activity. These mutants exhibited a number of distinct phenotypic characteristics and altered abilities with regard to phenotypic divergence. Results demonstrate the importance of PM-ATPase in overall physiology of this pathogenic yeast.