Studies investigating the value of Marker Assisted Selection (MAS) for increasing genetic gain have compared responses from MAS and conventional schemes obtained with standard truncation selection and have ignored rates of inbreeding, DF (e.g. Ruane and Colleau, 1995). On the other hand, research comparing schemes at the same ΔF using optimised selection (Villanueva et al. 1999) has assumed that the effect of the QTL is known without error. This study extends the optimisation methods to include selection on genetic markers rather than on the QTL itself.