In order to determine the part played in facial dissymmetry observed on a living person by the various constitutive elements of the cephalic tip (the soft parts - skin, muscles and the underlying bone structure) we undertook, using a biostereometric method, to evaluate asymmetries between homologous right and left dimensions on a living person's face and on a skeleton. While in an individual, a marked degree of facial dissymmetry can sometimes be observed; average differences between the right and left sides of the face may nethertheless balance out, and remain slight. Conventional anthropometrics techniques do not show up such slight values. With a view to securing a higher degree of accuracy, study of the stereometric technique of measurements. Using this technique, quasi imperceptible differences between the right and the left sides of the face on a living person as well as on a skeleton, together with variations in the orientation or angulation of anatomical segments in a three-dimensional space can be measured. We were thus able to detect, in a number of dry skulls, average differences of approxi-mately a millimetre between the two sides of the face which cannot be attributed to back of accuracy in measurements. Although statistically the difference are not always significant, the para-metric values of facial dimensions are invariably greater for the left side. On the other hand, for the sample of living subjects as a whole, the differences between homologous distances are not statistically significant. But it may be that, on a living subject, the experimenter is inclined to take measurements that are susceptible of symmetrization (for instance, the nasion in the median sagittal plane) whereas on a dry skull anatomical reference marks can be determined with the utmost accuracy. It may be inferred from there results that the softer parts tend, as a rule, to correct the dissymmetry of the underlying skeleton.