The curing reaction of the diglycidyl ether of bisphenol A with different diglycidyls and triglycidyls (used as diluents) using 2,2-bis[4-(p-aminophenoxy)phenyl]propane as a curing agent, with or without fortifier, has been studied by differential scanning calorimetry. The thermal stability of the cured resins has also been discussed. The overall activation energy for the curing reaction is observed to be in the range 48.1–71.4 kJ mol−1 and the order of the reaction is found to be ∼-1.0. The activation energy of decomposition of the cured resin falls within the range 48.3–84.5 kJ mol−1.