The possibility of using granulated slags resulting from the smelting of lead and zinc in partial, or total replacement of sand in mortars and concretes, has been examined. The major components of these vitreous slags are Ca, Si, Fe and Al compounds with lead concentration of a few percent. They have suitable particle sizes for use as sand and the slag mortars and concretes studied here yielded satisfactory mechanical strengths. The extraction of lead by acid eluants might however create some problems when concretes containing these slags have to be disposed off.