The rising drop technique was used to study the kinetics of the alkaline hydrolysis of two formate esters; n-butylformate and iso-amylformate in toluene formed the organic phase, whilst aqueous sodium hydroxide was used as the continuous phase. The effects of ester and alkali concentrations on the rate of the hydrolysis were studied. The order of the reaction was found to change with respect to the concentration of both reactants. Cetyltrimethylammoniumbromide (CTAB) was used as a possible catalyst for this liquid-liquid hydrolysis. When CTAB was added to the aqueous phase, enhancement of reaction was observed, whilst its addition to the organic phase caused inhibition of the hydrolysis. It is suggested that the enhancement of the reaction is due to the interaction of micelles in proximity to the interface while the inhibition is probably due to chemical blocking of the interface by adsorbed molecules of ionized CTAB.