Although cranial bones reliably identify the features of mammals, these traits can be affected by sex, population size and seasonality. This paper biometrically analyses the cranial features of the common vole. The research sample consisted of adult (n = 134), subadult (n = 57), of western Slovakia. Overall, software based on the highlighted marks measured 29 cranial features. Significant sexual dimorphism was observed for three features in adult individuals (width of the maxillary tooth row – right side “WMTRR”, maximum height of the mandibula excluding coronoid process “AMdm” and coronoid height of the mandibula “AMd”) and four features in subadults (length of the tooth row in the maxilla “LOSD”, “WMTRR”, length of the molar “LoM” and alveolar length of the lower molars “ALLM”). Results showed a significant positive relationship between body weight and cranial size in 18 of the 29 features. They also suggested a weak but significant positive effect of common vole abundance on cranium size (Chitty effect) likewise in 6 of the 29 features. In several cases, this effect affects, in addition to the abundance, the onset of sexual maturity of individuals.