Mixtures of esters produced by reacting a mixture of aromatic and aliphatic monocarboxylic acids with a diol containing from 2 to 12 carbon atoms are effective plasticizers for plastisols containing dispersion grade polymers of vinyl chloride. The freezing point of the present ester mixtures and their efficacy as plasticizers can be varied by adjusting the type and relative concentration of the aliphatic acid used to prepare the plasticizer. The ester mixtures can also be used as plasticizers for other organic polymers.