Drug impurity profiling, i.e. identification, structure elucidation and quantitative determination of impurities and degradation products in bulk drug materials and pharmaceutical formulations is one of the most important fields of activities in modern pharmaceutical analysis. The reason for the increased importance of this area is that unidentified, potentially toxic impurities are health hazards and in order to increase the safety of drug therapy, impurities should be identified and determined by selective methods. The number of papers dealing with drug impurity profiling is high and the rate is continuously increasing. The aim of this review is to characterise the state-of-the-art in the field of impurity profiling of drugs based mainly on papers published in the last 5 years. The main areas, discussed in this review are separation and determination of impurities with known structure, off-line and on-line chromatographic – spectroscopic methods for the structure elucidation of impurities and degradation products as well as some selected topics such as impurity issues in compendia, genotoxic impurities and analytical aspects of enantiomeric purity of chiral drugs. The points of view of the selection of papers for the review and their discussion are • papers with interesting chemical background i.e. where the impurities are products of interesting side reactions of the synthesis or products of interesting degradation reactions, and • papers where up to date on-line methods (HPLC-MS, HPLC-NMR, etc.) played predominant role in the structure elucidation.