Understanding space use by endangered species is important for conserving their populations, especially in locations that have a great degree of human activity. Transmitters that provide high spatial resolution have only recently become available for small-bodied animals and show promise for providing new information on habitat use. However, as with any new technology it is important to assess adverse effects on study species. We tested the efficacy of using 1.1-g miniaturized GPS units to document the breeding and post-breeding movements of adult Piping Plovers (Charadrius melodus) from the federally threatened Atlantic Coast population. We also assessed the potential impact of these miniaturized GPS units on nest survival, chick survival, and apparent adult survival rates. We found that Piping Plover movements to and from nesting areas were related to tidal stage, we documented Piping Plovers to be using previously undocumented foraging areas during the breeding season, and we obtained fine resolution habitat use data for two birds on their wintering areas in the Bahamas. The attachment of a GPS tag had no effect on apparent weekly survival of adults, and we found no differences in daily nest survival and chick survival rates between pairs with GPS tags and controls. GPS tags did not appear to adversely impact Piping Plovers during the breeding season, yet lower return rates of GPS tagged birds than controls might suggest potential negative effects on survival. While GPS tags offer a valuable tool to evaluate habitat use of this threatened species on the breeding grounds, long-term tracking needs further investigation.