Transdermal drug delivery represents one of the most rapidly advancing areas of novel drug delivery. Although the concept of transdermal drug delivery has been known since 1924, it took until 1979, as FDA approved the transdermal delivery of scopolamine, that transdermal delivery systems [TDDS] received broad attention as novel tool for controlled release. These drug delivery systems are designed for controlled release of drug through the skin into systemic circulation maintaining consistent efficacy and reducing dose of the drug and its related side effects. More than 200 patents have been granted by the United State patent alone, of which more than 35 TDD products have now been approved for sale in the US, and approximately 16 active ingredients have been approved for use globally. Statistics reveal a market of $ 12.7 billion in the year 2005 which is expected to increase by $ 21.5 billion in the year 2010 and $ 31.5 billion in the year 2015. Almost all major and minor pharmaceutical companies are developing TDDS. There is not a single review article which describes patents on different types of TDDS. Thus this review is designed for patents on the different type of TDDS which would be helpful for the researcher in the field of TDDS.