The nucleophilic hydrolysis of paraoxon, parathion and fenitrothion by pyridine oximate (PyOx(-)) and hydroxamate (PyHA(-)) has been studied in aqueous and cationic micellar media. A noticeable kinetic changes has been observed at pH > pK (a) due to effective nucleophilicity of oximate (-CH=NO-) and hydroxamate (-CONHO-) functions. The Ox(-) nucleophile shows large reactivity than corresponding HA(-). The reactivity of nucleophiles toward the electrophilic center of P=O and P=S bond of phosphate ester shows prominent effect in the presence of cetyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB) micelles than aqueous media. The adjacent lone pair of electron in nitrogen atom on the nucleophile moiety of 2-PyOx and 2-PyHA helps to augment the reactivity compared to presence in remote of 4-PyOx and 4-PyHA nucleophile. The application of the pseudophase model of micellar catalysis showed that the ratio k (2) (m)/k (2) (w) is higher for the reaction of esters. [GRAPHICS] .