In 2006, the CCAMLR Scientific Committee expressed concern as to the status of the stock on which the exploratory Dissostichus spp. fishery on BANZARE Bank (CCAMLR Division 58.4.3b) was based. This paper presents a summary of fine-scale catch and effort data held by CCAMLR for BANZARE Bank, as well as descriptive analyses of biological data submitted by scientific observers on board vessels in the fishery. Results of a Leslie depletion analysis of stratified catch and effort data indicate that there is strong evidence for depletion of toothfish at the scale of individual fishing grounds in the 2004/05 and 2005/06 seasons. This result, coupled with high estimated levels of illegal, unreported and unregulated (IUU) fishing, and evidence of poor recent recruitment, indicates that the stock is likely to have been overfished. Several inconsistencies are noted between historical data and those submitted in the 2006/07 season, with Patagonian toothfish (D. eleginoides) reportedly replacing Antarctic toothfish (D. mawsoni) as the dominant toothfish species in catches in one ground for the first time. Incomplete reporting of biological information for by-catch species by on-board scientific observers was noted, limiting meaningful analysis of patterns in by-catch catch and effort. Further research, particularly research surveys, would greatly assist with assessing the status and stock structure of Dissostichus spp. in this area. The potential for similar analyses in other exploratory toothfish fisheries should be investigated, as this study indicates that severe depletion can occur in the space of just two or three seasons.