Parmar et al.: Recent Analytical Techniques for Characterization of ImpuritiesImpurity is an unwanted substance present in the active pharmaceutical ingredients that form during the synthesis process of active pharmaceutical ingredients or any unwanted constituent that is produced besides the active ingredient during the formulation or the aging of active pharmaceutical ingredients. Even the insignificant quantity of impurity existing in the medicinal product may harm the patient life and compromises the purity and superiority of the medicinal product. According to International council for harmonisation guidelines, analytical monitoring of impurity is a prerequisite and mandatory requirement for approval of market authorization of the new drug substance. Any pharmaceutical product would be capable to serve their intended therapeutic activity when they are free from impurity. Thus, an impurity existing in an active pharmaceutical ingredient needs to be identified and quantify with the help of modern analytical approaches. This review explores the basic information concerning impurity profiling, highlights the advantages of an analytical technique and also focuses on the limitation of different analytical methods for impurity profiling with possible ways to overcome the limitation.