The literature survey presented in this review shows that the knowledge regarding the structure of various siderophores and the presence of microbial membrane receptors that operates in iron uptake from these iron – siderophore complexes have opened newer avenues for research. Siderophores and their substituted derivatives have a large number of applications in medical sciences. The most important application is selective drug delivery, a Trojan horse strategy, to defeat drug resistant bacteria. The Trojan horse strategy is most promising way to specifically attack multiple antibiotic resistant strains of bacteria associated with life threatening infections. Other major clinical applications include treatment of diseases like haemochromatosis, thalassemia, dialysis encephalopathy, removal of transuranic elements such as aluminium and vanadium and anti-malarial activity.