Barrier islands are popular recreational areas of economic importance and are constantly undergoing change. Costly efforts are made to maintain beaches and stabilize dunes within this dynamic environment. Light detection and ranging data collected in September 1997 and 1998 along a 175-km stretch of the Atlantic coast of the Outer Banks, North Carolina, provide the basis for quantitative determination of the changes in beach morphology. The 1998 survey was conducted just after the passage of Hurricane Bonnie. During the 1-year study interval, beach widths throughout the study region tended to decrease. Maximum dune retreat was determined for each 1-m bin of 1997 beach width. For comparable beach widths, maximum dune retreat increased from south to north. The maximum dune retreat was greatest for supratidal beaches with widths of ∼20 m. For wider supratidal beaches, from 20 to 60 m, the associated maximum dune retreat gradually decreased. There was no further decrease in maximum dune retreat for beaches wider than ∼60 m. Relatively little change in beach width, dune height, and dune base position occurred along the less developed beaches of the Core Banks. The greatest morphological changes occurred on Ocracoke Island and Hatteras Island. Of the geomorphic parameters examined, preexisting beach width and the dune base elevation were the best indicators of vulnerability to dune retreat.