A subantarctic population of the Fairy Prion (Pachyptila turtur) was studied at South Georgia in 1982-83. Full measurements of breeding birds are given, together with details of breeding habitat, the timing of the main breeding cycle events, and chick growth (weight and wing, culmen and tarsus length). Regurgitated food samples showed the diet to be mainly Crustacea (96% by weight), fish and squid comprising the rest. Of crustaceans, Antarctic krill made up 38% of items and 80% by weight. Copepods (four species, mostly Rhincalanus gigas) made up 39% of items but only 4% by weight; amphipods [three species, principally Themisto gaudichaudii made up 22% of items and 16% by weight. Diet and frequency of chick feeding are compared with those of Antarctic Prions and Blue Petrels at the same site; Fairy Prions are essentially intermediate.