Kinetic and mechanistic studies of saponification of seven structurally related and industrially important diesters have been investigated. Time ratio method and Swain's standard data for series first order reactions have been utilized for the evaluation of rate data and thermodynamic parameters viz. DeltaE*,-DeltaH*, DeltaG*,DeltaS* and log A for both the steps which involve the competitive and consecutive saponification reactions which also indicate the first step of saponification processes is quite faster than the second step and further more the laurates are more saponifiable than stearates and oleostearate in 72% alcohol-water moiety and in general these processes are much faster in acetone-water, dioxane-water, DMSO-water and DMF-water systems than in alcohol-water system.