The volume of the cranial cavity of 70 dogs (35 males and 35 females) has been determined in two breeds, the galgo greyhound and the pointer, by radiological techniques (computerized tomography; CT) and biostatistical methods. Each head was submitted to a complete series of transverse tomographic sections taken perpendicularly to the basilar plane, every 5 mm and with a thickness of 5 mm. There is a clear difference between the breeds and the two sexes, with a minimal confidence of 99.95%. The application of the method to fit zootechnical and/or osteoarcheological needs is emphasized.