Six men and six women participated in a study designed to compare adhesion-to-skin measurements of three transdermal nitroglycerin patch formulations (Minitran, Transderm-Nitro 5, and Nitro-Dur II) with an occlusive surgical tape control. After 24 hours of wear, Minitran was found to be superior to the other three products in skin adhesion. The force required to remove Minitran was significantly higher than that required to remove the other products. Maintaining good skin contact over the entire application period is essential for consistent drug delivery. Improved skin contact can increase transdermal drug delivery. This increase in delivery of nitroglycerin may result in the development of smaller patches rated to deliver the same quantity of nitroglycerin over a 24-hour period.