Liquid-phase oxidation of 2-isopropylnaphthalene (2-IPN) to 2-isopropylnaphthalenehydroperoxide (2-IPNHP) was carried out in the presence of Cu2O, Cu2O+NaOHaq, CuO+NaOHaq, NaOHaq, NaOHs, Na2CO3s, Na2CO3aq, Na2O2 and 2-IPNHP as the initiator-catalysts and the effect of sodium on the oxidation rate and product distribution was investigated. CuO+NaOHaq, NaOHaq and Na2O2 showed the highest catalytic activity and selectivity for 2-IPNHP. The effect of catalyst concentration and temperature was investigated in the oxidations carried out by NaOHaq to achieve the maximum 2-IPNHP concentration and to minimize the production of dimethyl-2-naphthylcarbinol and 2-acetonaphthone as by-products. An oxidation network for 2-IPN was suggested by using the conversion-selectivity relationship. 1.257 mol dm(-3) 2-IPNHP was obtained from 6.9 mol dm(-3) 2-IPN with 26% conversion and 73% selectivity in the presence of NaOHaq, where Na+ concentration was 9.20x10(-3) g dm(-3), at 110 degrees C.