We estimated survival rates of adult Southern Buller's Albatrosses (Thalassarche bulleri bulleri) from 1948 to 1997 based on a long-term banding and recapture program at The Snares, New Zealand. Annual survival exceeded 0.95 from 1961 to 1968 and from 1992 to 1997 but declined to between 0.913 and 0.928 from 1969 to 1991. Reduced survival may have resulted from incidental mortality associated with longline and trawl fisheries in the foraging areas of these birds, but it must have been counterbalanced by changes in other population parameters because the population increased greatly in number from 1969 to 1997. Increased trawling activity in areas where albatrosses forage may have benefited the population by providing additional food, which may have enhanced the survival rate of recently fledged birds. We found no indication that survival rates differed between males and females, but an age effect occurred in which survival of birds with at least 25 years of breeding experience was lower than that of less-experienced and presumably younger birds.