By-catches of fish taken during a commercial fishing cruise and an experimental deep-sea longline fishing cruise targeting Patagonian toothfish (Dissostichus eleginoides) off the Kerguelen Islands (Division 58.5.1) during the 1995/96 season were analysed. Eleven species were identified, of which the grenadier Macrourus carinatus, the skates Bathyraja eatonii and B. irrasa and the morid Antimora rostrata were dominant. The others were mainly shelf-dwelling species found at the limit of their bathymetric range. An abundance index was used to show bathymetric and geographical distributions of the most common by-catch species. The size of some by-catch species shows that they could be of interest commercially if longline fishing operations expand in this part of the Southern Ocean in the future.