By-catch was observed during two successive cruises of longliners fishing for Patagonian toothfish Dissostichus eleginoides in approximately 500m depth along the shelf slope in the west of Kerguelen. By-catch consisted mainly of Rajidae Bathyraja spp. (85 %). The proportion of species taken in the by-catch was low (less than 0.75%) and does not represent a problem at the present level of fishing. The results indicate that longlining therefore is a highly target-specific method of fishing in the patagonian toothfish fishery.