All experimental variables involved in the stripping method were investigated in detail in order to identify the best working conditions. A fast, sensitive method for determining paraquat in oils (especially olive oil) is described. In principle, considering the extreme lipophilicity of the bipyridyl herbicides, it is quite unlikely to find such residues in olive oil. Nevertheless, they could appear at ppb levels. This is particularly critical in the case of organic oils which are, by definition, supposed not to contain pesticides. Therefore, we must ensure that such oils fulfill the legislation.