The properties of purified cell envelope polyphosphatase, polyphosphatase activities of vacuoles and cytosol fractions of the Saccharomyces cerevisiae yeast have been compared. The whole body of evidence presently available suggest that each of the compartments under study is equipped with its own polyphosphatase which differs from polyphosphatases of other organelles. It is proposed that the organelle specificity of yeast polyphosphatases may reflect the endosymbiotic origin of eucaryotic cells.