This book constitutes the proceedings of the 16th International Symposium on Graph Drawing, GD 2008, held in Heraklion, Crete, Greece, during September 21-24, 2008. The 31 long papers and 8 short papers presented together with 10 posters and two invited papers were carefully reviewed and selected from 83 submissions. The volume also includes a report on the Graph Drawing Contest which was held during the conference. An important aspect of the conference is bridging the gap between theoretical advances and implemented solutions of geometric representation of graphs and networks. It is motivated by those applications where it is crucial to visualize structural information as graphs.