Audouin's gull (Larus audouinii) eggshells from 2 archipelagos (Karaburun-lzmir and Aydincik-Mersin) in Turkey were collected between 2002 and 2003, and analyzed for lead (Pb) and copper (Cu) content. According to the results, mean Cu level of the eggshells was 1.855 ppm for the Aydincik colony and 10.202 ppm for the Karaburun colony. Mean Pb level of the eggshells was 0.954 ppm for the Aydincik colony and 4.601 ppm for the Karaburun colony. The detected metal levels did not seem to have any toxic effects on the Audouin's gull populations. It is suggested that eggshells from abandoned nests of Audouin's gulls may be useful as bio-indicators for monitoring heavy metal contamination.