Kinetic and mechanistic studies of saponification of the above structurally related and industrially important mono and diesters and their comparative behaviour of saponification process 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(not equal), -DeltaH(not equal), DeltaG(not equal), DeltaS(not equal) and log A for mono and diesters which involve the competitive and consecutive saponification reactions. These investigations also indicate that mono esters undergo saponification process much faster than diesters and furthermore, the oleostearates are more saponifiable than stearates. In general, these processes are much faster in dioxane-water, DMSO-water and DMF-water systems than in alcohol-water system. Further, the d(AB) (inter-ionic distance in the double sphere model of an activated complex) of mono esters are much smaller than diesters confirming that saponification processes are relatively faster in mono esters than diesters.