The correlation between coronary calcifications and subclinical atherosclerotic disease has been well known for some years now. Today we are able to quantify coronary calcium deposits, the calcium score, by means of new imaging techniques such as electron beam computed tomography and multislice spiral computed tomography. A large number of studies performed using these methods has confirmed the association between coronary calcifications and atherosclerotic disease and has opened up the possibility of early diagnosis of any subclinical atherosclerotic disease in various subpopulations such as diabetics and nephropatics. The etiopathogenesis of coronary calcium has not yet been made clear; it appears to be an active process similar to bone formation that involves cells similar to those involved in the reabsorption of bone matrix. The calcium score, therefore, provides physicians with a further diagnostic tool able to better determine cardiovascular risk patients and supplements the Framingham risk score. International guidelines have not yet illustrated with any precision in which ambits to apply screening for the quantification of coronary calcium and consequently, for the time being, the use of such methods must be restricted to cases in which the possibility of any benefit can be scientifically shown. This review represents the state of the art on coronary calcification and its role in clinical practice.