by certain features with respect to the environment in which they develop. We report here preliminary findings that for the first time to quantify size asymmetry mandibles of companion rabbits. A total sample of 64 companion rabbits from the same farm were studied by means of geometric morphometric techniques. The mandible morphology was described by a set of 18 landmarks and semil and marks on the lateral aspect. Tests showed paired differences with variations in distributions, demonstrating a DA in favour of left mandibular side. The detected unilaterality could be interpreted as a manifestation of lateralized masticatory activity. This is a first time report to quantify size asymmetry in this species.