Summary of the Heavy Flavor Working Group

During the last year many important results have been achieved in heavy flavour physics: New measurements of charm and beauty production have been performed at HERA and the Tevatron. A wealth of new spectroscopy data with several new, unexpected states in the charmonium and the D_s systems has been collected and b to d gamma transitions have been established. The oscillation frequency in the B_s Bbar_s is now measured, and mixing in the D0 D0bar system has been observed. Theoretical progress in the areas of open heavy flavour production, quarkonium production and decays, and multiquark spectroscopy has been presented at this workshop.