The concretes produced with barite (BaSO4) were studied as shielding materials for gamma-radiation. The concretes were prepared with different volumes of barite, and thus each concrete has different density and aggregate. The mass attenuation coefficients have been calculated at photon energies of I keV to 100 GeV using XCOM and the obtained results were compared with the measurements at 0.66 and 1.25 MeV. The barite concrete results were also compared with ordinary concretes. (C) 2004 Elsevier Ltd All rights reserved.