Williams-syndrome is a rare genetic disorder characterized by a specific developmental profile following damage to a sequence on chromosome 7. A basic feature of the WS cognitive profile is assumed to be a dissociation between verbal and spatial abilities. In the authors' studies spatial memory performance of WS children was compared with three matched control groups. These studies allow for the analysis of several methodological and theoretical issues concerning spatial memory. The central issue in their studies was the attempt to elaborate a new task to measure spatial memory based on ecologically familiar tasks. This is the so called Map task requiring long term learning of spatial reference points and paths. Using the Map task they were able to show impaired performance in subjects with Williams syndrome both in acquiring reference points and paths. Spatial working memory capacity had a clear influence on long term spatial learning. However, retention of reference points had a stronger relationship to working memory capacity than performance regarding paths. On the whole, the Map task seems to be a useful procedure to investigate the development of spatial memory abilities.