OLSON and WIJSMAN (1993) have proposed a robust linkage analysis between quantitative traits and a marker locus using all relative pairs. We extend their work to estimate the recombination fraction using a two-step procedure. In the first step Generalised Estimating Equations are solved. After robust linkage analysis minimum distance estimation is applied in the second step. Our approach requires a single codominant marker locus only. The relevant parameters of the genetic model can also be estimated by this method in the presence of linkage. We illustrate our approach by simulations.