During the 2005 fishing season, experiments on the survivorship of toothfish following tagging were carried out on eight different vessels fishing in Subarea 48.3. Toothfish were kept in tanks with seawater replacement for at least 12 hours after tagging. On one vessel, fish with a variety of injuries were selected to see if this affected recovery. In the final analysis, 396 animals were included, with an overall survivorship of 90%. Smaller animals and animals in better initial condition had a higher survivorship than large animals and those in poor condition. The results suggest that experienced observers using animals in good condition would normally achieve a toothfish post-tagging survivorship of 95% or more. An assumption of 90% post-tagging survivorship is a conservative value which might be appropriate to use in population estimators until further survivorship studies have confirmed the 95% rate.