A discrete wrist-worn transdermal alcohol monitoring device, the BACtrack® Skyn™, was evaluated in a subject over three drinking sessions. The relationship between transdermal alcohol concentration (TAC) and breath alcohol concentration (BrAC) was evaluated. The relationship amongst contemporaneous TAC/BrAC measurements revealed an R² of 0.65, while the relationship in the 45-minute post-drinking phase revealed an R² of 0.89. Results obtained show promise for its use. Further research is needed with many subjects in real-world drinking situations.