Between August and November 2001, two fishing vessels carried out exploratory and experimental surveys with semipelagic and different configurations of long line directed to the capture of Wreckfish (Polyprion americanus) and other fish species within the Uruguayan EEZ. Observers were trained in order to include Seabirds information along with their common tasks. Seabirds mortality associated with long line operation is analyzed, as well as species involved and mitigation measures application. Total mortality ranged: 3 birds/1 000 hooks, and main species captured were Procellaria aequinoctialis (50%), Puffinus gravis (27%) y Thalassarche melanophrys (21%). Bird species composition varied along the operation period. No significant differences in mortality were found between long line types, being higher in those with floats attached to the main line, and under daylight setting. Some species presence was consistent comparing their abundance during line setting and resulting mortality. Difficulties were found in mitigation measures application, specially to set during night only and avoiding bird scaring tangles with intermediate buoys. Although this fishery is no longer in Uruguay, the need to improve some information related to fishing gear and seabirds interaction is discussed, as well as the revision of current regulations.