The composition comprises a mixture of olive oil (Olea europea L.) and parsley oil (Petroselinum sativum Hoffm., Petroselinum crispum Mill., Carum petroselinum Benth & Hooker), in a ratio of olive oil: parsley oil, by weight, comprised between 1 and 7. Additionally the composition may contain other vegetable oils, mint oil, menthol and chlorophyll. These compositions may be presented in several forms including sweets, chewing-gum, dentifrice paste, mouthwashes and pharmaceutical compositions, especially as soft gelatine capsules, for which purpose they incorporate the suitable additives, vehicles and excipients for its processing in the desired form of presentation. The composition is suitable for the treatment of halitosis.