These proceedings contain the papers presented at VisSym '01, the third Joint Visuali zation Symposium of the Eurographics Association and the Technical Committee on Visualization and Graphics (TCVG) of the IEEE Computer Society. The symposium is being held from May 28 to May 30, 2001, in Ascona, Switzerland. The number of submitted papers has again increased to reach 68 this year and their high quality made it possible to extend the program to 33 presentations. VisSym has grown from a mostly European workshop to a visualization event of global signifi cance, which is best illustrated by the...