The fishery for Patagonian toothfish is one of the most valuable in the CCAMLR Area. Age based models are used to assess the status of the stocks of this species. Although age can be estimated using otoliths it has proven difficult for these to be validated. During a recent trawl survey the length density of juvenile toothfish in the catches had a clearly defined polymodal distribution. The age of each fish was estimated from the otoliths and the distribution of these ages matched closely the modal size groups. It is confirmed that one annulus, as seen on an otolith section, corresponds to one year’s growth.