The clinical results of drug eluting stents [DESs] depend on the type of the coating, the coating technology and the dosage and efficiency of the drug. The current study shows our examinations on drug eluting stents. Different types of commercially available coronary stents were investigated. Various methods were used for these experiments, for example optical microscopy, confocal fluorescent microscopy, scanning electron microscopy and EDS analysis. The properties characterizing applicability of drug eluting stents and the changing of the coatings during expansion are shown.