A modified potentiometric titration is proposed for the estimation of phenol in aqueous systems. The method is evolved on the basis of a critical dependence of pH on log V rather than simple V, as used in conventional potentiometric titrations. The method incorporates titrants in a concentration range several orders of magnitude greater than that of phenol in the aqueous phase. Derivative potentiometric curves so obtained provide a clear exposition of the equivalence point and the overall error is found to be between +/-1.0 and 1.5%. The range of phenol concentration investigated was from 10(-2) to 10(-3) M. and that of sodium hydroxide used as the titrant from 10(-1) to 4.0 M. The maximized titrant concentrations were found to be helpful in controlling the dilution problem during titration. The lowest detection limit achieved was 50 mg phenol/L and the method is well-suited to direct aqueous phase municipal sewage, home effluents and industrial discharges for phenol determination.