Effects of different factors, namely the concentration of nonionic surfactant Brij-30, content of water and the presence of kosmotropic and chaotropic ions in the water pockets of the reverse microemulsion, on the chromatographic behavior of some drugs were investigated by microemulsion liquid chromatography. Results show that retention factors of the model compounds are influenced by surfactant concentration and water content and also by the presence of different ions in the water core of the reverse micelle.