This volume represents the refereed proceedings of the Sixth International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scienti?c Computing which was held in conjunction with the Second International C- ference on Monte Carlo and Probabilistic Methods for Partial Di?erential Equations at Juan-les-Pins, France, from 7 10 June 2004. The programme of this conference was arranged by a committee consisting of Henri Faure (U- versit edeMarseille), PaulGlasserman(ColumbiaUniversity), StefanHeinrich (Universit] at Kaiserslautern), Fred J. Hickernell (Hong Kong Baptist Univ- sity),...