Transdermal drug delivery systems are topically administered medicaments in the form of patches that deliver for systemic effects at predetermined and control rate. Since last decade TDDS gained a lot of interest due to its advantages over the conventional dosage forms and oral controlled release delivery, notably avoidance of hepatic first pass effect. Optimizations of drug release through the skin into the systemic circulation and simultaneously minimize the metabolism of drug in the skin is the major goal of transdermal products. The market value of TDDS products are increasing with rapid rate ,more than 35 products have now been approved for sale in US and approximately 16 active ingredients approved globally for use as a TDDS. Transdermal drug delivery is a recent technology which promises a great future. It has a potential to limit the use of needles for administering wide variety of drugs but cost factor is an important thing to consider since developing nations like India is hidden part of TDDS therapy due to its higher cost. The present review outline the latest developments overall evaluation methods and technologies of TDDS.