Polyfluoroalkyl compounds (PFAs) have been used for decades in industrial and commercial products and are now detected worldwide. Concentrations of two major PFA groups, carboxylic acids (PFCAs) and sulfonic acids (PFSAs), were assessed in plasma of bottlenose dolphins from the Gulf of Mexico (Sarasota Bay, FL) and the Atlantic Ocean (Delaware Bay, NJ, Charleston, SC, Indian River Lagoon (IRL), FL, and Bermuda). Eight PFAs were detected in the plasma of all dolphins. Perfluorooctane sulfonate (PFOS) was the predominant compound at all locations (range from 49 ng/g wet weight (w.w.) in dolphins from Bermuda to 1171 ng/g w.w. in plasma of animals from Charleston). ; This document is the accepted manuscript version of a published work that appeared in final form in Environmental Science & Technology afterpeer review and technical editing by the publisher. To access the final edited and publishedwork see http://dx.doi.org/10.1021/es0506556. This article may be cited as: Houde, M.,Wells, R. S., Fair, P. A., Bossart, G. D., Hohn, A. A., Rowles, T. K., Sweeney, J. C., Solomon, K.R., & Muir, D. C. G. (2005). Polyfluoroalkyl Compounds in Free‐Ranging Bottlenose Dolphins (Tursiops truncatus) from the Gulf of Mexico and the Atlantic Ocean. Environmental Science & Technology, 39(17), 6591-6598. ; Florida Atlantic University. Harbor Branch Oceanographic Institute contribution #1615.