Fluorescence quenching of four naphthalenediols [1,5-; 1,7-; 2,7-; and 2,3- Naphthalenediols (NDs)] by inorganic anions [Clβ, Brβ, SO4 2β SO3 2β, S2O3 2β, CO3 2β, NO3 β, and HPO4 2β] have been studied in 95% (v/v) water βethanol mixture medium. The quenching was found to be dynamic in all systems. The plots of log kq values with singlet transition energy (Es) of the fluorophore and with ECTTS of the quencher are linear indicating the presence of electron transfer quenching mechanism. ΞGTH values for charge transfer quenching have been determined for naphthalenediols