The problem of drawing a pedigree in a clear and concise manner is discussed and a case is made for the adoption of the marriage node graph as the most appropriate format in which to depict highly looped pedigrees. A method for assigning suitable coordinates to marriages and individuals is then described. This involves use of simulated annealing to search for the clearest picture. The method is illustrated by two examples: the pedigree of Przewalski's Horse and that of the European Bison.