Application of nanomedical approaches in experimental and clinical oncology for cancer diagnosis and therapy is growing exponentially. The main efforts are currently directed towards the development of nanocarrier-based tumor-specific delivery systems for therapeutic and diagnostic agents. Several review papers and books published within last few months provide good illustration to how broad these efforts are [1-8]. Still, there is a common goal in all studies on cancer nanomedicine - to prepare therapeutic and diagnostic nanopreparations, which are capable of minimizing undesirable side effects of therapeutic and diagnostic agents onto normal tissues and organs and maximizing their accumulation in tumors. Certainly, in a single journal issue it is impossible to represent the existing variety of nanomedical approaches for cancer. The editor and the authors of this issue have been trying to pursue a more realistic goal - to provide potential readers with some biological and pharmacological backgrounds of cancer nanomedicine and illustrate the general approach with some representative examples showing how cancer nanotherapeutics are developed and investigated. The opening paper of this issue by Dr. Campbell addresses some key aspects of tumor physiology, which have to be taken into account when developing cancer nanotherapeutics. Specific attention is paid here to tumor vasculature and its role in tumor accumulation of drug-loaded nanocarriers. The paper by Dr. Allen and coauthors discusses the most important features of pharmacokinetics and pharmacodynamics of nanoparticles in cancer using lipidic nanocarriers as an example. Next three papers are dealing with certain specific types on pharmaceutical nanocarriers and their application for cancer therapy. Dr. Bae and coauthors describe properties and application of polymeric micelles, which are successfully used to increase the solubility and bioavailability of poorly soluble anticancer drugs, and specifically concentrate on such micelles that can changed their properties in a desirable way when exposed to acidified surroundings in tumors or even inside tumor cells. Dr. Minko and coauthors concentrate on current situation with the development of the liposomal drugs for cancer and discuss new, more sophisticated liposomal preparations loaded with multicomponent drug systems, which can simultaneously overcome drug efflux pumps and enhance apoptosis in cancer cells. Dr. Moghimi is considering polymeric nanoparticles and current status on their engineering and application both in experimental and clinical oncology. These three papers on individual types of pharmaceutical nanocarriers for cancer allow for more clear understanding of general problems associated with the application of nanosized drug delivery systems and show also the specifics in the development and application of each particular system. The last paper of the issue by Dr. Ogris brings to light achievements and challenges associated with the use of nanoparticlate delivery systems for nucleic acid therapy of cancer, promising and fast growing area of research. I believe that this issue will successfully introduce the readers to exciting and challenging area of cancer nanomedicine. References [1] Zamboni W.C. Clin Cancer Res, 2005, 11, 8230. [2] Huynh G.H.; Deen D.F.; Szoka F.G., Jr. J Control Release, 2006, 110, 236. [3] Cegnar M.; Kristl J.; Kos J. Expert Opin Biol Ther, 2005, 5, 1557. [4] Vicent M.J.; Duncan R. Trends Biotechnol, 2006, 24, 39. [5] Sapra P.; Tyagi P.; Allen T.M. Curr Drug Deliv, 2005, 2, 369. [6] van Vlerken L.E.; Amiji M.M. Expert Opin Drug Deliv, 2006, 3, 205. [7] Wu G.; Barth R.F.; Yang W.; Lee R.J.; Tjarks W.; Backer M.V.; Backer J.M. Anticancer Agents Med Chem, 2006, 6, 167. [8] Torchilin V.P.; Ed. Delivery of Protein and Peptide Drugs in Cancer, 2006, Imperial College Press, London, UK.