A new fluoride selective fluorescent receptor (13E,19E)-N1′,N3′-bis[4-(diethylamino)-2-hydroxybenzylidene]malonohydrazide (1) was designed and synthesized. Receptor 1 showed a highly selective fluorescent ‘turn-on’ response towards F − among the various tested anions such as F − , Cl − , Br − , I − , HSO 4 − , H 2 PO 4 − , NO 2 − and CN − in CH 3 OH:H 2 O (50:50, v/v), due to the formation of hydrogen bonding host–guest complex in 1:1 stoichiometry with a detection limit of 45.7nM and association constant of 1.0×10 4 M −1 . The nature of interactions between the receptor 1 and F − was investigated by 1 H NMR and the probable structure of the 1·F − complex was predicted by B3LYP/6-31G** method.