A QTL detection experiment was organized in a backcross Sarda X Lacaune sheep resource population. The first aim of this experiment was the search for loci influencing milk production and several other traits difficult to measure through a whole genome scan. However, Sarda and Lacaune sheep breeds differ for wool characteristics. The Lacaune sheep is a short wool breed while the Sarda is a long wool one with a fleece made of both long-coarse medullated fibre and short-finer wool fibre. The purpose of this paper is to give results about QTL detection on wool traits and fleece characteristics in this sheep population resource.