Use of nest materials for skuas (Catharacta spp.) and kelp gull (Larus dominicanus) was studied in the Antarctic Peninsula during the 1992-1993 breeding season. Material from 126 skua and 51 gull nests found in 10 habitat types (HTs) was analyzed. Plant censuses were conducted to evaluate the availability of species commonly used as nesting material. Skuas used mainly Polytrichum alpestre, while gulls used mainly Deschampsia antarctica. No correlation was found in the use of different nest material in skuas and gulls, indicating that they differ in their use. The narrow range of resources found in nest material suggests a selective pattern of use restricted to a few plant species. However, use of nesting material also appears linked to its availability, although skuas and gulls’ preference for P. alpestre and D. antarctica, respectively was observed in HTs with a low and discontinuous covering of these plant species.