James D. Bjorken, professor emeritus of physics, Stanford University, and Curtis G. Callan, professor of physics, Princeton University, USA, are the winners of the 2004 Dirac Medal. The announcement was made on the birth date of the prize's namesake, Nobel Laureate Paul A.M. Dirac, who was a close friend and strong advocate of the Centre. Bjorken and Callan are being honoured for theoretical investigations that led to the use of deep inelastic scattering for shedding light on the nature of strong interactions. The awards ceremony will take place at a later date. For additional information and the list of previous winners, see www.ictp.it.