A survey of seabirds breeding on Teuri Island (44°25′N, 141°19′E) was conducted in July 1984 and April to August 1985. The numbers of breeding pairs were estimated as Larus crassirostris, 29, 466 : L. schistisagus, 414 ; Phalacrocorax filamentosus, 766; P. pelagicus, 12; Uria aalge, 217; Cerorhinca monocerata, 172, 041. Synthliboramphus antiquus and Cepphus carbo also breed on the island. The two Larus species and P. filamentosus have increased in numbers, while U. aalge and C. carbo have decreased recently.